|
Path-Selection |
BGPv4 RFC 4271 |
Nokia |
Arista |
Cisco |
Juniper |
|
Non-standard |
|
|
Highest Weight |
Highest Weight |
Route Preference |
|
1 |
Highest LOCAL_PREF |
Highest LOCAL_PREF |
Highest LOCAL_PREF |
Highest LOCAL_PREF |
Highest LOCAL_PREF |
|
Non-standard |
|
|
|
Interior > Exterior > Exterior via Interior |
|
|
2 |
Shortest AS_PATH |
Shortest AS_PATH |
Shortest AS_PATH |
Shortest AS_PATH |
Shortest AS_PATH |
|
3 |
Lowest ORIGIN: IGP >EGP > Incomplete |
Lowest ORIGIN: IGP >EGP > Incomplete |
Lowest ORIGIN: IGP >EGP > Incomplete |
Lowest ORIGIN: IGP >EGP > Incomplete |
Lowest ORIGIN: IGP >EGP > Incomplete |
|
4 |
Lowest MED |
Lowest MED |
Lowest MED |
Lowest MED |
Lowest MED |
|
Non-standard |
|
|
|
|
Interior > Exterior > Exterior via Interior |
|
5 |
eBGP>iBGP |
eBGP>iBGP |
eBGP>iBGP |
eBGP>iBGP |
eBGP>iBGP |
|
6 |
Lowest IGP metric to NEXT_HOP |
Lowest IGP metric to NEXT_HOP |
Lowest IGP metric to NEXT_HOP |
Lowest IGP metric to NEXT_HOP |
Lowest IGP metric to NEXT_HOP |
|
Non-standard |
Multipath |
|
Multipath |
Multipath |
Multipath |
|
Non-standard |
Oldest active route |
Oldest active route |
Oldest active route |
Oldest active route |
Oldest active route |
|
7 |
Lowest ORIGINATOR_ID, or Router-ID |
Lowest ORIGINATOR_ID, or Router-ID |
Lowest ORIGINATOR_ID, or Router-ID |
Lowest ORIGINATOR_ID, or Router-ID |
Lowest ORIGINATOR_ID, or Router-ID |
|
8 (RFC4456 standard) |
Shortest CLUSTER_LIST |
Shortest CLUSTER_LIST |
Shortest CLUSTER_LIST |
Shortest CLUSTER_LIST |
Shortest CLUSTER_LIST |
|
9 |
Lowest peering address |
Lowest BGP peering address |
Lowest BGP peering address |
Lowest BGP peering address |
Lowest BGP peering address |
1. higher Local Preference
R3, R4에 local-preference 값을 100, 200으로 설정 한 뒤, R2에서 bgp best 경로를 확인해 보면,
|
A:R3>config>router# show router policy "upper" entry 10 from protocol static tag 100 exit to protocol bgp exit action accept origin igp local-preference 100 next-hop 30.1.1.1 exit exit |
*A:R4>config>router# show router policy "upper" entry 10 from protocol static tag 100 exit to protocol bgp exit action accept origin igp local-preference 200 next-hop 30.1.1.2 exit exit |
2기준에서 R3보다 R4의 경로가 우선시 되어야 한다. R2에서 확인해보면,
*A:R2>config>router# show router bgp routes 20.1.11.0/24
===============================================================================
BGP Router ID:2.2.2.2 AS:4766 Local AS:4766
===============================================================================
Legend -
Status codes : u - used, s - suppressed, h - history, d - decayed, * - valid
l - leaked, x - stale, > - best, b - backup, p - purge
Origin codes : i - IGP, e - EGP, ? - incomplete
===============================================================================
BGP IPv4 Routes
===============================================================================
Flag Network LocalPref MED
Nexthop (Router) Path-Id Label
As-Path
-------------------------------------------------------------------------------
u*>i 20.1.11.0/24 200 None
30.1.1.2 None -
No As-Path
*i 20.1.11.0/24 100 None
30.1.1.1 None -
No As-Path
-------------------------------------------------------------------------------
Routes : 2
bgp의 경로가 local-preference의 값이 높은 R4쪽의 경로를 우선하는 것을 확인할 수 있으며,
TieBreakReason : LocalPref을 보아 R3으로의 경로는 local-preference 값이 낮은 것을 확인할 수 있다.
|
*A:R2>config>router# show router bgp routes 20.1.11.0/24 detail =============================================================================== BGP Router ID:2.2.2.2 AS:4766 Local AS:4766 =============================================================================== Legend - Status codes : u - used, s - suppressed, h - history, d - decayed, * - valid l - leaked, x - stale, > - best, b - backup, p - purge Origin codes : i - IGP, e - EGP, ? - incomplete
=============================================================================== BGP IPv4 Routes =============================================================================== Original Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.2 Path Id : None From : 4.4.4.4 Res. Nexthop : 10.1.12.2 Local Pref. : 200 Interface Name : Te1/1/1 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : None AIGP Metric : None Connector : None Community : No Community Members Cluster : No Cluster Members Originator Id : None Peer Router Id : 4.4.4.4 Fwd Class : None Priority : None Flags : Used Valid Best IGP Route Source : Internal AS-Path : No As-Path Route Tag : 0 Neighbor-AS : N/A Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h03m33s
Modified Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.2 Path Id : None From : 4.4.4.4 Res. Nexthop : 10.1.12.2 Local Pref. : 200 Interface Name : Te1/1/1 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : None AIGP Metric : None Connector : None Community : No Community Members Cluster : No Cluster Members Originator Id : None Peer Router Id : 4.4.4.4 Fwd Class : None Priority : None Flags : Used Valid Best IGP Route Source : Internal AS-Path : No As-Path Route Tag : 0 Neighbor-AS : N/A Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h03m36s
------------------------------------------------------------------------------- Original Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.1 Path Id : None From : 3.3.3.3 Res. Nexthop : 10.1.12.2 Local Pref. : 100 Interface Name : Te1/1/1 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : None AIGP Metric : None Connector : None Community : No Community Members Cluster : No Cluster Members Originator Id : None Peer Router Id : 3.3.3.3 Fwd Class : None Priority : None Flags : Valid IGP TieBreakReason : LocalPref Route Source : Internal AS-Path : No As-Path Route Tag : 0 Neighbor-AS : N/A Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h04m28s
Modified Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.1 Path Id : None From : 3.3.3.3 Res. Nexthop : 10.1.12.2 Local Pref. : 100 Interface Name : Te1/1/1 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : None AIGP Metric : None Connector : None Community : No Community Members Cluster : No Cluster Members Originator Id : None Peer Router Id : 3.3.3.3 Fwd Class : None Priority : None Flags : Valid IGP TieBreakReason : LocalPref Route Source : Internal AS-Path : No As-Path Route Tag : 0 Neighbor-AS : N/A Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h04m28s
------------------------------------------------------------------------------- ------------------------------------------------------------------------------- Routes : 2 |
2. shortest AS path
AS-Path는 해당 네트워크까지 가는 경로 상에 있는 AS 주소들을 기록해 놓는 속성이다. 이때, 해당 네트워크 정보가 소속된 AS 주소는 가장 오른쪽에 기록되며, AS와 AS 간에 라우팅 업데이트가 되면서 누적되는 AS 주소는 왼쪽 방향으로 차례대로 기록된다. 그리고 서로 다른 neighbor로부터 동일한 BGP 정보를 수신한다면, AS-Path 주소에 짧게 기록된 정보가 선출된다.
|
*A:R6>config>router# show router policy "upper" entry 10 from protocol static tag 100 exit to protocol bgp exit action accept as-path-prepend 500 1 origin igp next-hop 30.1.1.3 exit exit |
*A:R7>config>router# show router policy "upper" entry 10 from protocol static tag 100 exit to protocol bgp exit action accept as-path-prepend 500 1 origin igp next-hop 30.1.1.4 exit exit |
|
*A:R5>config>router# show router bgp routes 20.1.11.0/24 =============================================================================== BGP Router ID:5.5.5.5 AS:4766 Local AS:4766 =============================================================================== Legend - Status codes : u - used, s - suppressed, h - history, d - decayed, * - valid l - leaked, x - stale, > - best, b - backup, p - purge Origin codes : i - IGP, e - EGP, ? - incomplete
=============================================================================== BGP IPv4 Routes =============================================================================== Flag Network LocalPref MED Nexthop (Router) Path-Id Label As-Path ------------------------------------------------------------------------------- u*>i 20.1.11.0/24 100 None 30.1.1.3 None - 500 *i 20.1.11.0/24 None None 7.7.7.7 None - 4768 500 ------------------------------------------------------------------------------- Routes : 2 =============================================================================== |
20.1.11.0/24 NH 30.1.1.3의 경로가 best 경로로 나옴을 확인할 수 있다.
정리하자면 AS가 같아서 No As-Path가 나오는 건데
다른 AS로 부터 받은 경로는 AS-Path에 찍히기 때문에 Ibgp로 받은 정보가 더 우선시 되는 것이다.
또한 20.1.11.0/24 NH 7.7.7.7의 경로는 R7에서 20.1.11.0/24 NH 30.1.1.4로 BGP 재분배를 하였지만,
R7의 system IP로 나온 것으로 보아, ebgp간 받은 정보는 해당 라우터의 neighbor IP가 찍힘을 알 수 있다.
|
*A:R5>config>router# show router bgp routes 20.1.11.0/24 detail =============================================================================== BGP Router ID:5.5.5.5 AS:4766 Local AS:4766 =============================================================================== Legend - Status codes : u - used, s - suppressed, h - history, d - decayed, * - valid l - leaked, x - stale, > - best, b - backup, p - purge Origin codes : i - IGP, e - EGP, ? - incomplete
=============================================================================== BGP IPv4 Routes =============================================================================== Original Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.3 Path Id : None From : 6.6.6.6 Res. Nexthop : 10.1.23.1 Local Pref. : 100 Interface Name : Te1/1/3 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : None AIGP Metric : None Connector : None Community : No Community Members Cluster : No Cluster Members Originator Id : None Peer Router Id : 6.6.6.6 Fwd Class : None Priority : None Flags : Used Valid Best IGP Route Source : Internal AS-Path : 500 Route Tag : 0 Neighbor-AS : 500 Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 02h07m47s
Modified Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.3 Path Id : None From : 6.6.6.6 Res. Nexthop : 10.1.23.1 Local Pref. : 100 Interface Name : Te1/1/3 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : None AIGP Metric : None Connector : None Community : No Community Members Cluster : No Cluster Members Originator Id : None Peer Router Id : 6.6.6.6 Fwd Class : None Priority : None Flags : Used Valid Best IGP Route Source : Internal AS-Path : 500 Route Tag : 0 Neighbor-AS : 500 Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 02h07m47s
------------------------------------------------------------------------------- Original Attributes
Network : 20.1.11.0/24 Nexthop : 7.7.7.7 Path Id : None From : 7.7.7.7 Res. Nexthop : 10.1.23.1 Local Pref. : n/a Interface Name : Te1/1/3 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : None AIGP Metric : None Connector : None Community : No Community Members Cluster : No Cluster Members Originator Id : None Peer Router Id : 7.7.7.7 Fwd Class : None Priority : None Flags : Valid IGP TieBreakReason : ASPathLen Route Source : External AS-Path : 4768 500 Route Tag : 0 Neighbor-AS : 4768 Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h02m41s
Modified Attributes
Network : 20.1.11.0/24 Nexthop : 7.7.7.7 Path Id : None From : 7.7.7.7 Res. Nexthop : 10.1.23.1 Local Pref. : None Interface Name : Te1/1/3 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : None AIGP Metric : None Connector : None Community : No Community Members Cluster : No Cluster Members Originator Id : None Peer Router Id : 7.7.7.7 Fwd Class : None Priority : None Flags : Valid IGP TieBreakReason : ASPathLen Route Source : External AS-Path : 4768 500 Route Tag : 0 Neighbor-AS : 4768 Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h02m43s
------------------------------------------------------------------------------- ------------------------------------------------------------------------------- Routes : 2 |
ㅁ 1번, 2번 항목 비교(R1)
R1에서 local-preference와 as-path 경로 우선순위를 살펴보면,
R2에서의 local-preference과 R5의 as path 우선인 20.1.11.0/24 경로에 대해서
R1에서 bgp 경로 확인 결과 local-preference가 우선임을 확인할 수 있다.
|
A:R1# show router bgp routes 20.1.11.0/24 =============================================================================== BGP Router ID:1.1.1.1 AS:4766 Local AS:4766 =============================================================================== Legend - Status codes : u - used, s - suppressed, h - history, d - decayed, * - valid l - leaked, x - stale, > - best, b - backup, p - purge Origin codes : i - IGP, e - EGP, ? - incomplete
=============================================================================== BGP IPv4 Routes =============================================================================== Flag Network LocalPref MED Nexthop (Router) Path-Id Label As-Path ------------------------------------------------------------------------------- u*>i 20.1.11.0/24 200 None 30.1.1.2 None - No As-Path *i 20.1.11.0/24 100 None 30.1.1.3 None - No As-Path ------------------------------------------------------------------------------- Routes : 2 =============================================================================== |
|
*A:R2>show>router>bgp# show router bgp routes 20.1.11.0/24 detail =============================================================================== BGP Router ID:2.2.2.2 AS:4766 Local AS:4766 =============================================================================== Legend - Status codes : u - used, s - suppressed, h - history, d - decayed, * - valid l - leaked, x - stale, > - best, b - backup, p - purge Origin codes : i - IGP, e - EGP, ? - incomplete
=============================================================================== BGP IPv4 Routes =============================================================================== Original Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.2 Path Id : None From : 4.4.4.4 Res. Nexthop : 10.1.12.2 Local Pref. : 200 Interface Name : Te1/1/1 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : None AIGP Metric : None Connector : None Community : No Community Members Cluster : No Cluster Members Originator Id : None Peer Router Id : 4.4.4.4 Fwd Class : None Priority : None Flags : Used Valid Best IGP Route Source : Internal AS-Path : No As-Path Route Tag : 0 Neighbor-AS : N/A Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h00m04s
Modified Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.2 Path Id : None From : 4.4.4.4 Res. Nexthop : 10.1.12.2 Local Pref. : 200 Interface Name : Te1/1/1 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : None AIGP Metric : None Connector : None Community : No Community Members Cluster : No Cluster Members Originator Id : None Peer Router Id : 4.4.4.4 Fwd Class : None Priority : None Flags : Used Valid Best IGP Route Source : Internal AS-Path : No As-Path Route Tag : 0 Neighbor-AS : N/A Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h00m04s
------------------------------------------------------------------------------- Original Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.1 Path Id : None From : 3.3.3.3 Res. Nexthop : 10.1.12.2 Local Pref. : 100 Interface Name : Te1/1/1 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : None AIGP Metric : None Connector : None Community : No Community Members Cluster : No Cluster Members Originator Id : None Peer Router Id : 3.3.3.3 Fwd Class : None Priority : None Flags : Valid IGP TieBreakReason : LocalPref Route Source : Internal AS-Path : No As-Path Route Tag : 0 Neighbor-AS : N/A Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h03m34s
Modified Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.1 Path Id : None From : 3.3.3.3 Res. Nexthop : 10.1.12.2 Local Pref. : 100 Interface Name : Te1/1/1 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : None AIGP Metric : None Connector : None Community : No Community Members Cluster : No Cluster Members Originator Id : None Peer Router Id : 3.3.3.3 Fwd Class : None Priority : None Flags : Valid IGP TieBreakReason : LocalPref Route Source : Internal AS-Path : No As-Path Route Tag : 0 Neighbor-AS : N/A Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h03m36s
------------------------------------------------------------------------------- ------------------------------------------------------------------------------- Routes : 2 |
A:R5>config>router# show router bgp routes 20.1.11.0/24 detail =============================================================================== BGP Router ID:5.5.5.5 AS:4766 Local AS:4766 =============================================================================== Legend - Status codes : u - used, s - suppressed, h - history, d - decayed, * - valid l - leaked, x - stale, > - best, b - backup, p - purge Origin codes : i - IGP, e - EGP, ? - incomplete
=============================================================================== BGP IPv4 Routes =============================================================================== Original Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.3 Path Id : None From : 6.6.6.6 Res. Nexthop : 10.1.23.1 Local Pref. : 100 Interface Name : Te1/1/3 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : None AIGP Metric : None Connector : None Community : No Community Members Cluster : No Cluster Members Originator Id : None Peer Router Id : 6.6.6.6 Fwd Class : None Priority : None Flags : Used Valid Best IGP Route Source : Internal AS-Path : No As-Path Route Tag : 0 Neighbor-AS : N/A Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h02m31s
Modified Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.3 Path Id : None From : 6.6.6.6 Res. Nexthop : 10.1.23.1 Local Pref. : 100 Interface Name : Te1/1/3 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : None AIGP Metric : None Connector : None Community : No Community Members Cluster : No Cluster Members Originator Id : None Peer Router Id : 6.6.6.6 Fwd Class : None Priority : None Flags : Used Valid Best IGP Route Source : Internal AS-Path : No As-Path Route Tag : 0 Neighbor-AS : N/A Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h02m31s
------------------------------------------------------------------------------- Original Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.4 Path Id : None From : 7.7.7.7 Res. Nexthop : 10.1.23.1 Local Pref. : 100 Interface Name : Te1/1/3 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : None AIGP Metric : None Connector : None Community : No Community Members Cluster : No Cluster Members Originator Id : None Peer Router Id : 7.7.7.7 Fwd Class : None Priority : None Flags : Valid IGP TieBreakReason : ASPathLen Route Source : Internal AS-Path : 500 Route Tag : 0 Neighbor-AS : 500 Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h00m06s
Modified Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.4 Path Id : None From : 7.7.7.7 Res. Nexthop : 10.1.23.1 Local Pref. : 100 Interface Name : Te1/1/3 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : None AIGP Metric : None Connector : None Community : No Community Members Cluster : No Cluster Members Originator Id : None Peer Router Id : 7.7.7.7 Fwd Class : None Priority : None Flags : Valid IGP TieBreakReason : ASPathLen Route Source : Internal AS-Path : 500 Route Tag : 0 Neighbor-AS : 500 Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h00m10s
------------------------------------------------------------------------------- ------------------------------------------------------------------------------- Routes : 2 |
local-preference가 우선임을 알 수 있다.
|
*A:R1>config>router# show router bgp routes 20.1.11.0/24 =============================================================================== BGP Router ID:1.1.1.1 AS:4766 Local AS:4766 =============================================================================== Legend - Status codes : u - used, s - suppressed, h - history, d - decayed, * - valid l - leaked, x - stale, > - best, b - backup, p - purge Origin codes : i - IGP, e - EGP, ? - incomplete
=============================================================================== BGP IPv4 Routes =============================================================================== Flag Network LocalPref MED Nexthop (Router) Path-Id Label As-Path ------------------------------------------------------------------------------- u*>i 20.1.11.0/24 200 None 30.1.1.2 None - No As-Path *i 20.1.11.0/24 100 None 30.1.1.3 None - 500 ------------------------------------------------------------------------------- Routes : 2 ===============================================================================
*A:R1>config>router# show router bgp routes 20.1.11.0/24 detail =============================================================================== BGP Router ID:1.1.1.1 AS:4766 Local AS:4766 =============================================================================== Legend - Status codes : u - used, s - suppressed, h - history, d - decayed, * - valid l - leaked, x - stale, > - best, b - backup, p - purge Origin codes : i - IGP, e - EGP, ? - incomplete
=============================================================================== BGP IPv4 Routes =============================================================================== Original Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.2 Path Id : None From : 2.2.2.2 Res. Nexthop : 10.1.11.2 Local Pref. : 200 Interface Name : Te1/1/1 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : None AIGP Metric : None Connector : None Community : No Community Members Cluster : 2.2.2.2 Originator Id : 4.4.4.4 Peer Router Id : 2.2.2.2 Fwd Class : None Priority : None Flags : Used Valid Best IGP Route Source : Internal AS-Path : No As-Path Route Tag : 0 Neighbor-AS : N/A Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h03m20s
Modified Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.2 Path Id : None From : 2.2.2.2 Res. Nexthop : 10.1.11.2 Local Pref. : 200 Interface Name : Te1/1/1 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : None AIGP Metric : None Connector : None Community : No Community Members Cluster : 2.2.2.2 Originator Id : 4.4.4.4 Peer Router Id : 2.2.2.2 Fwd Class : None Priority : None Flags : Used Valid Best IGP Route Source : Internal AS-Path : No As-Path Route Tag : 0 Neighbor-AS : N/A Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h03m20s
------------------------------------------------------------------------------- Original Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.3 Path Id : None From : 5.5.5.5 Res. Nexthop : 10.1.11.2 Local Pref. : 100 Interface Name : Te1/1/1 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : None AIGP Metric : None Connector : None Community : No Community Members Cluster : 5.5.5.5 Originator Id : 6.6.6.6 Peer Router Id : 5.5.5.5 Fwd Class : None Priority : None Flags : Valid IGP TieBreakReason : LocalPref Route Source : Internal AS-Path : 500 Route Tag : 0 Neighbor-AS : 500 Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h12m20s
Modified Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.3 Path Id : None From : 5.5.5.5 Res. Nexthop : 10.1.11.2 Local Pref. : 100 Interface Name : Te1/1/1 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : None AIGP Metric : None Connector : None Community : No Community Members Cluster : 5.5.5.5 Originator Id : 6.6.6.6 Peer Router Id : 5.5.5.5 Fwd Class : None Priority : None Flags : Valid IGP TieBreakReason : LocalPref Route Source : Internal AS-Path : 500 Route Tag : 0 Neighbor-AS : 500 Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h12m20s
------------------------------------------------------------------------------- ------------------------------------------------------------------------------- Routes : 2 |
3. low Origin
lower origin have preference: IGP = 0, EGP = 1, INCOMPLETE = 2
해당 항목은 origin 코드를 보고 IGP를 우선한다는 내용이다.
R3을 origin code igp, R4는 origin code egp로 설정 후 R2에서 확인해 보면
igp인 R3의 경로가 우선임을 알 수 있다.
|
*A:R3>config>router# show router policy "upper" entry 10 from protocol static tag 100 exit to protocol bgp exit action accept as-path-prepend 500 1 origin igp local-preference 100 next-hop 30.1.1.1 exit exit |
*A:R4>config>router# show router policy "upper" entry 10 from protocol static tag 100 exit to protocol bgp exit action accept as-path-prepend 500 1 origin egp local-preference 100 next-hop 30.1.1.2 exit exit |
|
*A:R2>config>router>bgp# show router bgp routes 20.1.11.0/24 =============================================================================== BGP Router ID:2.2.2.2 AS:4766 Local AS:4766 =============================================================================== Legend - Status codes : u - used, s - suppressed, h - history, d - decayed, * - valid l - leaked, x - stale, > - best, b - backup, p - purge Origin codes : i - IGP, e - EGP, ? - incomplete
=============================================================================== BGP IPv4 Routes =============================================================================== Flag Network LocalPref MED Nexthop (Router) Path-Id Label As-Path ------------------------------------------------------------------------------- u*>i 20.1.11.0/24 100 None 30.1.1.1 None - No As-Path *e 20.1.11.0/24 100 None 30.1.1.2 None - No As-Path ------------------------------------------------------------------------------- Routes : 2 =============================================================================== |
|
A:R2>config# show router bgp routes 20.1.11.0/24 detail =============================================================================== BGP Router ID:2.2.2.2 AS:4766 Local AS:4766 =============================================================================== Legend - Status codes : u - used, s - suppressed, h - history, d - decayed, * - valid l - leaked, x - stale, > - best, b - backup, p - purge Origin codes : i - IGP, e - EGP, ? - incomplete
=============================================================================== BGP IPv4 Routes =============================================================================== Original Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.1 Path Id : None From : 3.3.3.3 Res. Nexthop : 10.1.12.2 Local Pref. : 100 Interface Name : Te1/1/1 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : None AIGP Metric : None Connector : None Community : No Community Members Cluster : No Cluster Members Originator Id : None Peer Router Id : 3.3.3.3 Fwd Class : None Priority : None Flags : Used Valid Best IGP Route Source : Internal AS-Path : No As-Path Route Tag : 0 Neighbor-AS : N/A Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 06h04m28s
Modified Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.1 Path Id : None From : 3.3.3.3 Res. Nexthop : 10.1.12.2 Local Pref. : 100 Interface Name : Te1/1/1 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : None AIGP Metric : None Connector : None Community : No Community Members Cluster : No Cluster Members Originator Id : None Peer Router Id : 3.3.3.3 Fwd Class : None Priority : None Flags : Used Valid Best IGP Route Source : Internal AS-Path : No As-Path Route Tag : 0 Neighbor-AS : N/A Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 06h04m29s
------------------------------------------------------------------------------- Original Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.2 Path Id : None From : 4.4.4.4 Res. Nexthop : 10.1.12.2 Local Pref. : 100 Interface Name : Te1/1/1 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : None AIGP Metric : None Connector : None Community : No Community Members Cluster : No Cluster Members Originator Id : None Peer Router Id : 4.4.4.4 Fwd Class : None Priority : None Flags : Valid EGP TieBreakReason : Origin Route Source : Internal AS-Path : No As-Path Route Tag : 0 Neighbor-AS : N/A Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h04m38s
Modified Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.2 Path Id : None From : 4.4.4.4 Res. Nexthop : 10.1.12.2 Local Pref. : 100 Interface Name : Te1/1/1 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : None AIGP Metric : None Connector : None Community : No Community Members Cluster : No Cluster Members Originator Id : None Peer Router Id : 4.4.4.4 Fwd Class : None Priority : None Flags : Valid EGP TieBreakReason : Origin Route Source : Internal AS-Path : No As-Path Route Tag : 0 Neighbor-AS : N/A Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h04m38s
------------------------------------------------------------------------------- ------------------------------------------------------------------------------- Routes : 2 =============================================================================== |
ㅁ 2번, 3번 비교
R2와 R5에서 best 정보를 해보면,
|
*A:R2>config>router>bgp# show router bgp routes 20.1.11.0/24 =============================================================================== BGP Router ID:2.2.2.2 AS:4766 Local AS:4766 =============================================================================== Legend - Status codes : u - used, s - suppressed, h - history, d - decayed, * - valid l - leaked, x - stale, > - best, b - backup, p - purge Origin codes : i - IGP, e - EGP, ? - incomplete
=============================================================================== BGP IPv4 Routes =============================================================================== Flag Network LocalPref MED Nexthop (Router) Path-Id Label As-Path ------------------------------------------------------------------------------- u*>i 20.1.11.0/24 100 None 30.1.1.1 None - 500 *e 20.1.11.0/24 100 None 30.1.1.2 None - 500 ------------------------------------------------------------------------------- Routes : 2 =============================================================================== *A:R2>config>router>bgp# show router bgp routes 20.1.11.0/24 detail =============================================================================== BGP Router ID:2.2.2.2 AS:4766 Local AS:4766 =============================================================================== Legend - Status codes : u - used, s - suppressed, h - history, d - decayed, * - valid l - leaked, x - stale, > - best, b - backup, p - purge Origin codes : i - IGP, e - EGP, ? - incomplete
=============================================================================== BGP IPv4 Routes =============================================================================== Original Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.1 Path Id : None From : 3.3.3.3 Res. Nexthop : 10.1.12.2 Local Pref. : 100 Interface Name : Te1/1/1 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : None AIGP Metric : None Connector : None Community : No Community Members Cluster : No Cluster Members Originator Id : None Peer Router Id : 3.3.3.3 Fwd Class : None Priority : None Flags : Used Valid Best IGP Route Source : Internal AS-Path : 500 Route Tag : 0 Neighbor-AS : 500 Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h08m14s
Modified Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.1 Path Id : None From : 3.3.3.3 Res. Nexthop : 10.1.12.2 Local Pref. : 100 Interface Name : Te1/1/1 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : None AIGP Metric : None Connector : None Community : No Community Members Cluster : No Cluster Members Originator Id : None Peer Router Id : 3.3.3.3 Fwd Class : None Priority : None Flags : Used Valid Best IGP Route Source : Internal AS-Path : 500 Route Tag : 0 Neighbor-AS : 500 Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h08m15s
------------------------------------------------------------------------------- Original Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.2 Path Id : None From : 4.4.4.4 Res. Nexthop : 10.1.12.2 Local Pref. : 100 Interface Name : Te1/1/1 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : None AIGP Metric : None Connector : None Community : No Community Members Cluster : No Cluster Members Originator Id : None Peer Router Id : 4.4.4.4 Fwd Class : None Priority : None Flags : Valid EGP TieBreakReason : Origin Route Source : Internal AS-Path : 500 Route Tag : 0 Neighbor-AS : 500 Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h00m47s
Modified Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.2 Path Id : None From : 4.4.4.4 Res. Nexthop : 10.1.12.2 Local Pref. : 100 Interface Name : Te1/1/1 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : None AIGP Metric : None Connector : None Community : No Community Members Cluster : No Cluster Members Originator Id : None Peer Router Id : 4.4.4.4 Fwd Class : None Priority : None Flags : Valid EGP TieBreakReason : Origin Route Source : Internal AS-Path : 500 Route Tag : 0 Neighbor-AS : 500 Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h00m47s
------------------------------------------------------------------------------- ------------------------------------------------------------------------------- Routes : 2 |
A:R5>config>router# show router bgp routes 20.1.11.0/24 =============================================================================== BGP Router ID:5.5.5.5 AS:4766 Local AS:4766 =============================================================================== Legend - Status codes : u - used, s - suppressed, h - history, d - decayed, * - valid l - leaked, x - stale, > - best, b - backup, p - purge Origin codes : i - IGP, e - EGP, ? - incomplete
=============================================================================== BGP IPv4 Routes =============================================================================== Flag Network LocalPref MED Nexthop (Router) Path-Id Label As-Path ------------------------------------------------------------------------------- u*>i 20.1.11.0/24 100 None 30.1.1.3 None - 500 *i 20.1.11.0/24 None None 7.7.7.7 None - 4768 500 ------------------------------------------------------------------------------- Routes : 2 =============================================================================== *A:R5>config>router# show router bgp routes 20.1.11.0/24 detail =============================================================================== BGP Router ID:5.5.5.5 AS:4766 Local AS:4766 =============================================================================== Legend - Status codes : u - used, s - suppressed, h - history, d - decayed, * - valid l - leaked, x - stale, > - best, b - backup, p - purge Origin codes : i - IGP, e - EGP, ? - incomplete
=============================================================================== BGP IPv4 Routes =============================================================================== Original Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.3 Path Id : None From : 6.6.6.6 Res. Nexthop : 10.1.23.1 Local Pref. : 100 Interface Name : Te1/1/3 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : None AIGP Metric : None Connector : None Community : No Community Members Cluster : No Cluster Members Originator Id : None Peer Router Id : 6.6.6.6 Fwd Class : None Priority : None Flags : Used Valid Best IGP Route Source : Internal AS-Path : 500 Route Tag : 0 Neighbor-AS : 500 Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 02h18m48s
Modified Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.3 Path Id : None From : 6.6.6.6 Res. Nexthop : 10.1.23.1 Local Pref. : 100 Interface Name : Te1/1/3 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : None AIGP Metric : None Connector : None Community : No Community Members Cluster : No Cluster Members Originator Id : None Peer Router Id : 6.6.6.6 Fwd Class : None Priority : None Flags : Used Valid Best IGP Route Source : Internal AS-Path : 500 Route Tag : 0 Neighbor-AS : 500 Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 02h18m49s
------------------------------------------------------------------------------- Original Attributes
Network : 20.1.11.0/24 Nexthop : 7.7.7.7 Path Id : None From : 7.7.7.7 Res. Nexthop : 10.1.23.1 Local Pref. : n/a Interface Name : Te1/1/3 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : None AIGP Metric : None Connector : None Community : No Community Members Cluster : No Cluster Members Originator Id : None Peer Router Id : 7.7.7.7 Fwd Class : None Priority : None Flags : Valid IGP TieBreakReason : ASPathLen Route Source : External AS-Path : 4768 500 Route Tag : 0 Neighbor-AS : 4768 Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h13m43s
Modified Attributes
Network : 20.1.11.0/24 Nexthop : 7.7.7.7 Path Id : None From : 7.7.7.7 Res. Nexthop : 10.1.23.1 Local Pref. : None Interface Name : Te1/1/3 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : None AIGP Metric : None Connector : None Community : No Community Members Cluster : No Cluster Members Originator Id : None Peer Router Id : 7.7.7.7 Fwd Class : None Priority : None Flags : Valid IGP TieBreakReason : ASPathLen Route Source : External AS-Path : 4768 500 Route Tag : 0 Neighbor-AS : 4768 Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h13m43s
------------------------------------------------------------------------------- ------------------------------------------------------------------------------- Routes : 2 |
|
*A:R1>config>router# show router bgp routes 20.1.11.0/24 =============================================================================== BGP Router ID:1.1.1.1 AS:4766 Local AS:4766 =============================================================================== Legend - Status codes : u - used, s - suppressed, h - history, d - decayed, * - valid l - leaked, x - stale, > - best, b - backup, p - purge Origin codes : i - IGP, e - EGP, ? - incomplete
=============================================================================== BGP IPv4 Routes =============================================================================== Flag Network LocalPref MED Nexthop (Router) Path-Id Label As-Path ------------------------------------------------------------------------------- u*>i 20.1.11.0/24 100 None 30.1.1.1 None - 500 *i 20.1.11.0/24 100 None 30.1.1.3 None - 500 ------------------------------------------------------------------------------- Routes : 2 =============================================================================== *A:R1>config>router# show router bgp routes 20.1.11.0/24 detail =============================================================================== BGP Router ID:1.1.1.1 AS:4766 Local AS:4766 =============================================================================== Legend - Status codes : u - used, s - suppressed, h - history, d - decayed, * - valid l - leaked, x - stale, > - best, b - backup, p - purge Origin codes : i - IGP, e - EGP, ? - incomplete
=============================================================================== BGP IPv4 Routes =============================================================================== Original Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.1 Path Id : None From : 2.2.2.2 Res. Nexthop : 10.1.11.2 Local Pref. : 100 Interface Name : Te1/1/1 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : None AIGP Metric : None Connector : None Community : No Community Members Cluster : 2.2.2.2 Originator Id : 3.3.3.3 Peer Router Id : 2.2.2.2 Fwd Class : None Priority : None Flags : Used Valid Best IGP Route Source : Internal AS-Path : 500 Route Tag : 0 Neighbor-AS : 500 Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h09m09s
Modified Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.1 Path Id : None From : 2.2.2.2 Res. Nexthop : 10.1.11.2 Local Pref. : 100 Interface Name : Te1/1/1 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : None AIGP Metric : None Connector : None Community : No Community Members Cluster : 2.2.2.2 Originator Id : 3.3.3.3 Peer Router Id : 2.2.2.2 Fwd Class : None Priority : None Flags : Used Valid Best IGP Route Source : Internal AS-Path : 500 Route Tag : 0 Neighbor-AS : 500 Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h09m09s
------------------------------------------------------------------------------- Original Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.3 Path Id : None From : 5.5.5.5 Res. Nexthop : 10.1.11.2 Local Pref. : 100 Interface Name : Te1/1/1 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : None AIGP Metric : None Connector : None Community : No Community Members Cluster : 5.5.5.5 Originator Id : 6.6.6.6 Peer Router Id : 5.5.5.5 Fwd Class : None Priority : None Flags : Valid IGP TieBreakReason : OriginatorID Route Source : Internal AS-Path : 500 Route Tag : 0 Neighbor-AS : 500 Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h30m54s
Modified Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.3 Path Id : None From : 5.5.5.5 Res. Nexthop : 10.1.11.2 Local Pref. : 100 Interface Name : Te1/1/1 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : None AIGP Metric : None Connector : None Community : No Community Members Cluster : 5.5.5.5 Originator Id : 6.6.6.6 Peer Router Id : 5.5.5.5 Fwd Class : None Priority : None Flags : Valid IGP TieBreakReason : OriginatorID Route Source : Internal AS-Path : 500 Route Tag : 0 Neighbor-AS : 500 Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h30m55s
------------------------------------------------------------------------------- ------------------------------------------------------------------------------- Routes : 2 =============================================================================== |
R2와 R5에서 동일한 20.1.11.0/24 NH 30.1.1.1(3)의 정보를 R1으로 올리게 되는데
local-preference값과 as-path가 동일하므로, Originator ID값을 비교하여 작은 R3에서 광고한
정보가 best로 잡히게 됩니다.
R3 ~ R6의 Originator ID를 동일하게 10.10.10.10으로 설정한 뒤, 비교해보면
|
*A:R1>config>router# show router bgp routes 20.1.11.0/24 =============================================================================== BGP Router ID:1.1.1.1 AS:4766 Local AS:4766 =============================================================================== Legend - Status codes : u - used, s - suppressed, h - history, d - decayed, * - valid l - leaked, x - stale, > - best, b - backup, p - purge Origin codes : i - IGP, e - EGP, ? - incomplete
=============================================================================== BGP IPv4 Routes =============================================================================== Flag Network LocalPref MED Nexthop (Router) Path-Id Label As-Path ------------------------------------------------------------------------------- u*>i 20.1.11.0/24 100 None 30.1.1.1 None - 500 *i 20.1.11.0/24 100 None 30.1.1.3 None - 500 ------------------------------------------------------------------------------- Routes : 2 ===============================================================================
*A:R1>config>router# show router bgp routes 20.1.11.0/24 detail =============================================================================== BGP Router ID:1.1.1.1 AS:4766 Local AS:4766 =============================================================================== Legend - Status codes : u - used, s - suppressed, h - history, d - decayed, * - valid l - leaked, x - stale, > - best, b - backup, p - purge Origin codes : i - IGP, e - EGP, ? - incomplete
=============================================================================== BGP IPv4 Routes =============================================================================== Original Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.1 Path Id : None From : 2.2.2.2 Res. Nexthop : 10.1.11.2 Local Pref. : 100 Interface Name : Te1/1/1 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : None AIGP Metric : None Connector : None Community : No Community Members Cluster : 2.2.2.2 Originator Id : 10.10.10.10 Peer Router Id : 2.2.2.2 Fwd Class : None Priority : None Flags : Used Valid Best IGP Route Source : Internal AS-Path : 500 Route Tag : 0 Neighbor-AS : 500 Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h00m49s
Modified Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.1 Path Id : None From : 2.2.2.2 Res. Nexthop : 10.1.11.2 Local Pref. : 100 Interface Name : Te1/1/1 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : None AIGP Metric : None Connector : None Community : No Community Members Cluster : 2.2.2.2 Originator Id : 10.10.10.10 Peer Router Id : 2.2.2.2 Fwd Class : None Priority : None Flags : Used Valid Best IGP Route Source : Internal AS-Path : 500 Route Tag : 0 Neighbor-AS : 500 Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h00m49s
------------------------------------------------------------------------------- Original Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.3 Path Id : None From : 5.5.5.5 Res. Nexthop : 10.1.11.2 Local Pref. : 100 Interface Name : Te1/1/1 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : None AIGP Metric : None Connector : None Community : No Community Members Cluster : 5.5.5.5 Originator Id : 10.10.10.10 Peer Router Id : 5.5.5.5 Fwd Class : None Priority : None Flags : Valid IGP TieBreakReason : PeerIP Route Source : Internal AS-Path : 500 Route Tag : 0 Neighbor-AS : 500 Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h00m26s
Modified Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.3 Path Id : None From : 5.5.5.5 Res. Nexthop : 10.1.11.2 Local Pref. : 100 Interface Name : Te1/1/1 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : None AIGP Metric : None Connector : None Community : No Community Members Cluster : 5.5.5.5 Originator Id : 10.10.10.10 Peer Router Id : 5.5.5.5 Fwd Class : None Priority : None Flags : Valid IGP TieBreakReason : PeerIP Route Source : Internal AS-Path : 500 Route Tag : 0 Neighbor-AS : 500 Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h00m26s
------------------------------------------------------------------------------- ------------------------------------------------------------------------------- Routes : 2 ===============================================================================
|
Peer IP를 비교하여 작은 쪽인 R2가 광고한 대역을 best로 잡고 있습니다.
4. lowest MED
|
*A:R3>config>router>bgp# info ---------------------------------------------- min-route-advertisement 1 med-out 100 export "upper" next-hop-resolution use-bgp-routes exit group "Uplink" family ipv4 neighbor 2.2.2.2 peer-as 4766 exit exit no shutdown ---------------------------------------------- |
*A:R4>config>router>bgp# info ---------------------------------------------- min-route-advertisement 1 med-out 200 export "upper" next-hop-resolution use-bgp-routes exit group "Uplink" family ipv4 neighbor 2.2.2.2 peer-as 4766 exit exit no shutdown ---------------------------------------------- |
|
A:R3>config>router# show router policy "upper" entry 10 from protocol static tag 100 exit to protocol bgp exit action accept as-path-prepend 500 1 origin igp local-preference 100 next-hop 30.1.1.1 exit exit |
*A:R4>config>router# show router policy "upper" entry 10 from protocol static tag 100 exit to protocol bgp exit action accept as-path-prepend 500 1 origin igp local-preference 100 next-hop 30.1.1.2 exit exit |
|
*A:R2>config>router>bgp# show router bgp routes 20.1.11.0/24 =============================================================================== BGP Router ID:2.2.2.2 AS:4766 Local AS:4766 =============================================================================== Legend - Status codes : u - used, s - suppressed, h - history, d - decayed, * - valid l - leaked, x - stale, > - best, b - backup, p - purge Origin codes : i - IGP, e - EGP, ? - incomplete
=============================================================================== BGP IPv4 Routes =============================================================================== Flag Network LocalPref MED Nexthop (Router) Path-Id Label As-Path ------------------------------------------------------------------------------- u*>i 20.1.11.0/24 100 100 30.1.1.1 None - 500 *i 20.1.11.0/24 100 200 30.1.1.2 None - 500 ------------------------------------------------------------------------------- Routes : 2 =============================================================================== |
|
*A:R2>config>router>bgp# show router bgp routes 20.1.11.0/24 detail =============================================================================== BGP Router ID:2.2.2.2 AS:4766 Local AS:4766 =============================================================================== Legend - Status codes : u - used, s - suppressed, h - history, d - decayed, * - valid l - leaked, x - stale, > - best, b - backup, p - purge Origin codes : i - IGP, e - EGP, ? - incomplete
=============================================================================== BGP IPv4 Routes =============================================================================== Original Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.1 Path Id : None From : 3.3.3.3 Res. Nexthop : 10.1.12.2 Local Pref. : 100 Interface Name : Te1/1/1 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : 100 AIGP Metric : None Connector : None Community : No Community Members Cluster : No Cluster Members Originator Id : None Peer Router Id : 3.3.3.3 Fwd Class : None Priority : None Flags : Used Valid Best IGP Route Source : Internal AS-Path : 500 Route Tag : 0 Neighbor-AS : 500 Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h00m13s
Modified Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.1 Path Id : None From : 3.3.3.3 Res. Nexthop : 10.1.12.2 Local Pref. : 100 Interface Name : Te1/1/1 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : 100 AIGP Metric : None Connector : None Community : No Community Members Cluster : No Cluster Members Originator Id : None Peer Router Id : 3.3.3.3 Fwd Class : None Priority : None Flags : Used Valid Best IGP Route Source : Internal AS-Path : 500 Route Tag : 0 Neighbor-AS : 500 Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h00m13s
------------------------------------------------------------------------------- Original Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.2 Path Id : None From : 4.4.4.4 Res. Nexthop : 10.1.12.2 Local Pref. : 100 Interface Name : Te1/1/1 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : 200 AIGP Metric : None Connector : None Community : No Community Members Cluster : No Cluster Members Originator Id : None Peer Router Id : 4.4.4.4 Fwd Class : None Priority : None Flags : Valid IGP TieBreakReason : MED Route Source : Internal AS-Path : 500 Route Tag : 0 Neighbor-AS : 500 Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h00m07s
Modified Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.2 Path Id : None From : 4.4.4.4 Res. Nexthop : 10.1.12.2 Local Pref. : 100 Interface Name : Te1/1/1 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : 200 AIGP Metric : None Connector : None Community : No Community Members Cluster : No Cluster Members Originator Id : None Peer Router Id : 4.4.4.4 Fwd Class : None Priority : None Flags : Valid IGP TieBreakReason : MED Route Source : Internal AS-Path : 500 Route Tag : 0 Neighbor-AS : 500 Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h00m07s
------------------------------------------------------------------------------- ------------------------------------------------------------------------------- Routes : 2 =============================================================================== |
ㅁ3번, 4번 비교
R2와 R5를 비교하여 med 값과 origin 간 best 경로를 확인해 보면,
|
*A:R2>config>router>bgp# show router bgp routes 20.1.11.0/24 =============================================================================== BGP Router ID:2.2.2.2 AS:4766 Local AS:4766 =============================================================================== Legend - Status codes : u - used, s - suppressed, h - history, d - decayed, * - valid l - leaked, x - stale, > - best, b - backup, p - purge Origin codes : i - IGP, e - EGP, ? - incomplete
=============================================================================== BGP IPv4 Routes =============================================================================== Flag Network LocalPref MED Nexthop (Router) Path-Id Label As-Path ------------------------------------------------------------------------------- u*>i 20.1.11.0/24 100 100 30.1.1.1 None - 500 *i 20.1.11.0/24 100 200 30.1.1.2 None - 500 ------------------------------------------------------------------------------- Routes : 2 =============================================================================== *A:R2>config>router>bgp# show router bgp routes 20.1.11.0/24 detail =============================================================================== BGP Router ID:2.2.2.2 AS:4766 Local AS:4766 =============================================================================== Legend - Status codes : u - used, s - suppressed, h - history, d - decayed, * - valid l - leaked, x - stale, > - best, b - backup, p - purge Origin codes : i - IGP, e - EGP, ? - incomplete
=============================================================================== BGP IPv4 Routes =============================================================================== Original Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.1 Path Id : None From : 3.3.3.3 Res. Nexthop : 10.1.12.2 Local Pref. : 100 Interface Name : Te1/1/1 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : 100 AIGP Metric : None Connector : None Community : No Community Members Cluster : No Cluster Members Originator Id : None Peer Router Id : 3.3.3.3 Fwd Class : None Priority : None Flags : Used Valid Best IGP Route Source : Internal AS-Path : 500 Route Tag : 0 Neighbor-AS : 500 Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h03m17s
Modified Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.1 Path Id : None From : 3.3.3.3 Res. Nexthop : 10.1.12.2 Local Pref. : 100 Interface Name : Te1/1/1 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : 100 AIGP Metric : None Connector : None Community : No Community Members Cluster : No Cluster Members Originator Id : None Peer Router Id : 3.3.3.3 Fwd Class : None Priority : None Flags : Used Valid Best IGP Route Source : Internal AS-Path : 500 Route Tag : 0 Neighbor-AS : 500 Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h03m17s
------------------------------------------------------------------------------- Original Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.2 Path Id : None From : 4.4.4.4 Res. Nexthop : 10.1.12.2 Local Pref. : 100 Interface Name : Te1/1/1 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : 200 AIGP Metric : None Connector : None Community : No Community Members Cluster : No Cluster Members Originator Id : None Peer Router Id : 4.4.4.4 Fwd Class : None Priority : None Flags : Valid IGP TieBreakReason : MED Route Source : Internal AS-Path : 500 Route Tag : 0 Neighbor-AS : 500 Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h03m11s
Modified Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.2 Path Id : None From : 4.4.4.4 Res. Nexthop : 10.1.12.2 Local Pref. : 100 Interface Name : Te1/1/1 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : 200 AIGP Metric : None Connector : None Community : No Community Members Cluster : No Cluster Members Originator Id : None Peer Router Id : 4.4.4.4 Fwd Class : None Priority : None Flags : Valid IGP TieBreakReason : MED Route Source : Internal AS-Path : 500 Route Tag : 0 Neighbor-AS : 500 Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h03m13s
------------------------------------------------------------------------------- ------------------------------------------------------------------------------- Routes : 2 =============================================================================== |
*A:R5>config>router>bgp# show router bgp routes 20.1.11.0/24 =============================================================================== BGP Router ID:5.5.5.5 AS:4766 Local AS:4766 =============================================================================== Legend - Status codes : u - used, s - suppressed, h - history, d - decayed, * - valid l - leaked, x - stale, > - best, b - backup, p - purge Origin codes : i - IGP, e - EGP, ? - incomplete
=============================================================================== BGP IPv4 Routes =============================================================================== Flag Network LocalPref MED Nexthop (Router) Path-Id Label As-Path ------------------------------------------------------------------------------- u*>i 20.1.11.0/24 100 None 30.1.1.3 None - 500 *e 20.1.11.0/24 100 None 30.1.1.4 None - 500 ------------------------------------------------------------------------------- Routes : 2 =============================================================================== *A:R5>config>router>bgp# show router bgp routes 20.1.11.0/24 detail =============================================================================== BGP Router ID:5.5.5.5 AS:4766 Local AS:4766 =============================================================================== Legend - Status codes : u - used, s - suppressed, h - history, d - decayed, * - valid l - leaked, x - stale, > - best, b - backup, p - purge Origin codes : i - IGP, e - EGP, ? - incomplete
=============================================================================== BGP IPv4 Routes =============================================================================== Original Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.3 Path Id : None From : 6.6.6.6 Res. Nexthop : 10.1.23.1 Local Pref. : 100 Interface Name : Te1/1/3 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : None AIGP Metric : None Connector : None Community : No Community Members Cluster : No Cluster Members Originator Id : None Peer Router Id : 6.6.6.6 Fwd Class : None Priority : None Flags : Used Valid Best IGP Route Source : Internal AS-Path : 500 Route Tag : 0 Neighbor-AS : 500 Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h03m14s
Modified Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.3 Path Id : None From : 6.6.6.6 Res. Nexthop : 10.1.23.1 Local Pref. : 100 Interface Name : Te1/1/3 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : None AIGP Metric : None Connector : None Community : No Community Members Cluster : No Cluster Members Originator Id : None Peer Router Id : 6.6.6.6 Fwd Class : None Priority : None Flags : Used Valid Best IGP Route Source : Internal AS-Path : 500 Route Tag : 0 Neighbor-AS : 500 Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h03m14s
------------------------------------------------------------------------------- Original Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.4 Path Id : None From : 7.7.7.7 Res. Nexthop : 10.1.23.1 Local Pref. : 100 Interface Name : Te1/1/3 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : None AIGP Metric : None Connector : None Community : No Community Members Cluster : No Cluster Members Originator Id : None Peer Router Id : 7.7.7.7 Fwd Class : None Priority : None Flags : Valid EGP TieBreakReason : Origin Route Source : Internal AS-Path : 500 Route Tag : 0 Neighbor-AS : 500 Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h00m56s
Modified Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.4 Path Id : None From : 7.7.7.7 Res. Nexthop : 10.1.23.1 Local Pref. : 100 Interface Name : Te1/1/3 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : None AIGP Metric : None Connector : None Community : No Community Members Cluster : No Cluster Members Originator Id : None Peer Router Id : 7.7.7.7 Fwd Class : None Priority : None Flags : Valid EGP TieBreakReason : Origin Route Source : Internal AS-Path : 500 Route Tag : 0 Neighbor-AS : 500 Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h00m57s
------------------------------------------------------------------------------- ------------------------------------------------------------------------------- Routes : 2 =============================================================================== |
|
*A:R1>config>router# show router bgp routes 20.1.11.0/24 =============================================================================== BGP Router ID:1.1.1.1 AS:4766 Local AS:4766 =============================================================================== Legend - Status codes : u - used, s - suppressed, h - history, d - decayed, * - valid l - leaked, x - stale, > - best, b - backup, p - purge Origin codes : i - IGP, e - EGP, ? - incomplete
=============================================================================== BGP IPv4 Routes =============================================================================== Flag Network LocalPref MED Nexthop (Router) Path-Id Label As-Path ------------------------------------------------------------------------------- u*>i 20.1.11.0/24 100 None 30.1.1.3 None - 500 *i 20.1.11.0/24 100 100 30.1.1.1 None - 500 ------------------------------------------------------------------------------- Routes : 2 ===============================================================================
R2과 R5의 동등한 경로를 R1으로 올리게 됩니다. R2은 med값 100 우선으로, R5는 origin igp 우선으로 올리게 되는데 R5의 경우 R6, R7이 med값을 설정하지 않아 med 값이 낮아 우선하게 됩니다. R6, R7의 med 값을 50으로 200으로 바꿀경우, 다른 라우터로 부터 받은 best 경로를 잡습니다.
*A:R1>config>router# show router bgp routes 20.1.11.0/24 detail =============================================================================== BGP Router ID:1.1.1.1 AS:4766 Local AS:4766 =============================================================================== Legend - Status codes : u - used, s - suppressed, h - history, d - decayed, * - valid l - leaked, x - stale, > - best, b - backup, p - purge Origin codes : i - IGP, e - EGP, ? - incomplete
=============================================================================== BGP IPv4 Routes =============================================================================== Original Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.3 Path Id : None From : 5.5.5.5 Res. Nexthop : 10.1.11.2 Local Pref. : 100 Interface Name : Te1/1/1 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : None AIGP Metric : None Connector : None Community : No Community Members Cluster : 5.5.5.5 Originator Id : 6.6.6.6 Peer Router Id : 5.5.5.5 Fwd Class : None Priority : None Flags : Used Valid Best IGP Route Source : Internal AS-Path : 500 Route Tag : 0 Neighbor-AS : 500 Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h05m42s
Modified Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.3 Path Id : None From : 5.5.5.5 Res. Nexthop : 10.1.11.2 Local Pref. : 100 Interface Name : Te1/1/1 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : None AIGP Metric : None Connector : None Community : No Community Members Cluster : 5.5.5.5 Originator Id : 6.6.6.6 Peer Router Id : 5.5.5.5 Fwd Class : None Priority : None Flags : Used Valid Best IGP Route Source : Internal AS-Path : 500 Route Tag : 0 Neighbor-AS : 500 Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h05m42s
------------------------------------------------------------------------------- Original Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.1 Path Id : None From : 2.2.2.2 Res. Nexthop : 10.1.11.2 Local Pref. : 100 Interface Name : Te1/1/1 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : 100 AIGP Metric : None Connector : None Community : No Community Members Cluster : 2.2.2.2 Originator Id : 3.3.3.3 Peer Router Id : 2.2.2.2 Fwd Class : None Priority : None Flags : Valid IGP TieBreakReason : MED Route Source : Internal AS-Path : 500 Route Tag : 0 Neighbor-AS : 500 Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h05m52s
Modified Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.1 Path Id : None From : 2.2.2.2 Res. Nexthop : 10.1.11.2 Local Pref. : 100 Interface Name : Te1/1/1 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : 100 AIGP Metric : None Connector : None Community : No Community Members Cluster : 2.2.2.2 Originator Id : 3.3.3.3 Peer Router Id : 2.2.2.2 Fwd Class : None Priority : None Flags : Valid IGP TieBreakReason : MED Route Source : Internal AS-Path : 500 Route Tag : 0 Neighbor-AS : 500 Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h05m56s
------------------------------------------------------------------------------- ------------------------------------------------------------------------------- Routes : 2 =============================================================================== |
5. EBGP peer > IBGP peer
|
*A:R6>config>router>bgp# show router policy "upper" entry 10 from protocol static tag 100 exit to protocol bgp exit action accept as-path-prepend 500 1 origin igp next-hop 30.1.1.3 exit exit
*A:R6>config>router>bgp# *A:R6>config>router>bgp# info ---------------------------------------------- min-route-advertisement 1 export "upper" router-id 10.10.10.10 next-hop-resolution use-bgp-routes exit group "Uplink" family ipv4 neighbor 5.5.5.5 local-as 4766 peer-as 4766 exit exit no shutdown
|
*A:R7>config>router# show router policy "upper" entry 10 from protocol static tag 100 exit to protocol bgp exit action accept origin igp next-hop 30.1.1.4 exit exit
*A:R7>config>router>bgp# info ---------------------------------------------- min-route-advertisement 1 export "upper" local-as 4766 router-id 10.10.10.10 next-hop-resolution use-bgp-routes exit group "Uplink" family ipv4 neighbor 5.5.5.5 local-as 4768 peer-as 4766 exit exit no shutdown ----------------------------------------------
|
서로 다른 as로 부터 들어온 정보라는 기준을 맞추기 위해
as-path-pretend를 각각 같은 as를 붙여서 확인해 보면
R5 - R6 간 IBGP(AS4766)
R5 - R7 간 eBGP(AS4768) 관계일 때,
R5에서 bgp routes를 확인해 보면,
|
*A:R5>config>router>bgp# show router bgp routes 20.1.11.0/24 =============================================================================== BGP Router ID:5.5.5.5 AS:4766 Local AS:4766 =============================================================================== Legend - Status codes : u - used, s - suppressed, h - history, d - decayed, * - valid l - leaked, x - stale, > - best, b - backup, p - purge Origin codes : i - IGP, e - EGP, ? - incomplete
=============================================================================== BGP IPv4 Routes =============================================================================== Flag Network LocalPref MED Nexthop (Router) Path-Id Label As-Path ------------------------------------------------------------------------------- u*>i 20.1.11.0/24 100 100 30.1.1.3 None - No As-Path *i 20.1.11.0/24 None 100 7.7.7.7 None - 4768 ------------------------------------------------------------------------------- Routes : 2 =============================================================================== |
위와 같이 iBGP로의 경로가 as-path때문에 우선됨을 알 수 있다.
R7 같은 경웅는 eBGP 관계이기 때문에 as-path가 찍혀있는 반면
ibgp인 R6은 같은 AS이기 때문에 No As-Path가 찍혀있어 TieBreakReason은 as-path로 인해
iBGP인 경로가 우선시 되는 것을 알 수 있다.
그렇기 때문에 iBGP관계인 R6에 as-prefend를 붙여 iBGP, eBGP간 as 정보를 R5에게 광고하게
테스트 해보면
|
*A:R5>config>router>bgp# show router bgp routes 20.1.11.0/24 =============================================================================== BGP Router ID:5.5.5.5 AS:4766 Local AS:4766 =============================================================================== Legend - Status codes : u - used, s - suppressed, h - history, d - decayed, * - valid l - leaked, x - stale, > - best, b - backup, p - purge Origin codes : i - IGP, e - EGP, ? - incomplete
=============================================================================== BGP IPv4 Routes =============================================================================== Flag Network LocalPref MED Nexthop (Router) Path-Id Label As-Path ------------------------------------------------------------------------------- u*>i 20.1.11.0/24 None 100 7.7.7.7 None - 4768 *i 20.1.11.0/24 100 100 30.1.1.3 None - 500 ------------------------------------------------------------------------------- Routes : 2 =============================================================================== |
20.1.11.0/24 NH 7.7.7.7인 eBGP경로가 best 경로로 잡는 것을 확인할 수 있으며 detail 정보를 확인해보면
이유를 알 수 있다.
|
*A:R5>config>router>bgp# show router bgp routes 20.1.11.0/24 detail =============================================================================== BGP Router ID:5.5.5.5 AS:4766 Local AS:4766 =============================================================================== Legend - Status codes : u - used, s - suppressed, h - history, d - decayed, * - valid l - leaked, x - stale, > - best, b - backup, p - purge Origin codes : i - IGP, e - EGP, ? - incomplete
=============================================================================== BGP IPv4 Routes =============================================================================== Original Attributes
Network : 20.1.11.0/24 Nexthop : 7.7.7.7 Path Id : None From : 7.7.7.7 Res. Nexthop : 10.1.23.1 Local Pref. : n/a Interface Name : Te1/1/3 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : 100 AIGP Metric : None Connector : None Community : No Community Members Cluster : No Cluster Members Originator Id : None Peer Router Id : 7.7.7.7 Fwd Class : None Priority : None Flags : Used Valid Best IGP Route Source : External AS-Path : 4768 Route Tag : 0 Neighbor-AS : 4768 Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h06m59s
Modified Attributes
Network : 20.1.11.0/24 Nexthop : 7.7.7.7 Path Id : None From : 7.7.7.7 Res. Nexthop : 10.1.23.1 Local Pref. : None Interface Name : Te1/1/3 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : 100 AIGP Metric : None Connector : None Community : No Community Members Cluster : No Cluster Members Originator Id : None Peer Router Id : 7.7.7.7 Fwd Class : None Priority : None Flags : Used Valid Best IGP Route Source : External AS-Path : 4768 Route Tag : 0 Neighbor-AS : 4768 Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h07m00s
------------------------------------------------------------------------------- Original Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.3 Path Id : None From : 6.6.6.6 Res. Nexthop : 10.1.23.1 Local Pref. : 100 Interface Name : Te1/1/3 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : 100 AIGP Metric : None Connector : None Community : No Community Members Cluster : No Cluster Members Originator Id : None Peer Router Id : 6.6.6.6 Fwd Class : None Priority : None Flags : Valid IGP TieBreakReason : EBGPRoute Route Source : Internal AS-Path : 500 Route Tag : 0 Neighbor-AS : 500 Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h10m28s
Modified Attributes
Network : 20.1.11.0/24 Nexthop : 30.1.1.3 Path Id : None From : 6.6.6.6 Res. Nexthop : 10.1.23.1 Local Pref. : 100 Interface Name : Te1/1/3 Aggregator AS : None Aggregator : None Atomic Aggr. : Not Atomic MED : 100 AIGP Metric : None Connector : None Community : No Community Members Cluster : No Cluster Members Originator Id : None Peer Router Id : 6.6.6.6 Fwd Class : None Priority : None Flags : Valid IGP TieBreakReason : EBGPRoute Route Source : Internal AS-Path : 500 Route Tag : 0 Neighbor-AS : 500 Orig Validation: NotFound Source Class : 0 Dest Class : 0 Add Paths Send : Default Last Modified : 00h10m28s
------------------------------------------------------------------------------- ------------------------------------------------------------------------------- Routes : 2 =============================================================================== |
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