EIGRP Site-of-Origin
前提
・PE-CE間、CEどうしの接続それぞれEIGRP AS100
Before
iosv-6#sh ip ro eigrp | b Gate
Gateway of last resort is not set
8.0.0.0/32 is subnetted, 1 subnets
D 8.8.8.8 [90/130816] via 68.1.1.8, 00:40:31, GigabitEthernet0/1
58.0.0.0/24 is subnetted, 1 subnets
D 58.1.1.0 [90/3072] via 68.1.1.8, 00:40:31, GigabitEthernet0/1
[90/3072] via 16.1.1.1, 00:40:31, GigabitEthernet0/0
88.0.0.0/32 is subnetted, 1 subnets
D 88.88.88.88 [90/130816] via 68.1.1.8, 00:40:31, GigabitEthernet0/1
iosv-8#sh ip ro eigrp | b Gate
Gateway of last resort is not set
6.0.0.0/32 is subnetted, 1 subnets
D 6.6.6.6 [90/130816] via 68.1.1.6, 00:39:59, GigabitEthernet0/1
16.0.0.0/24 is subnetted, 1 subnets
D 16.1.1.0 [90/3072] via 68.1.1.6, 00:39:59, GigabitEthernet0/1
[90/3072] via 58.1.1.5, 00:39:59, GigabitEthernet0/0
66.0.0.0/32 is subnetted, 1 subnets
D 66.66.66.66 [90/130816] via 68.1.1.6, 00:39:59, GigabitEthernet0/1設定1: 異なるSoO
iosv-1(config)#route-map SOO permit 10
iosv-1(config-route-map)#set extcommunity soo 16:16
iosv-1(config-route-map)#exit
iosv-1(config)#int gi0/1
iosv-1(config-if)#ip vrf site
iosv-1(config-if)#ip vrf sitemap SOO
iosv-5(config)#route-map SOO permit 10
iosv-5(config-route-map)#set extcommunity soo 58:58
iosv-5(config-route-map)#exit
iosv-5(config)#int gi0/0
iosv-5(config-if)#ip vrf site
iosv-5(config-if)#ip vrf sitemap SOO確認1: show ip eigrp vrf topology
iosv-1#sh ip eigrp vrf bbb topo 58.1.1.0/24
EIGRP-IPv4 VR(cisco) Topology Entry for AS(100)/ID(16.1.1.1)
Topology(base) TID(0) VRF(bbb)
EIGRP-IPv4(100): Topology base(0) entry for 58.1.1.0/24
State is Passive, Query origin flag is 1, 1 Successor(s), FD is 1310720
Descriptor Blocks:
5.5.5.5, from VPNv4 Sourced, Send flag is 0x0
Composite metric is (1310720/0), route is Internal (VPNv4 Sourced)
Vector metric:
Minimum bandwidth is 1000000 Kbit
Total delay is 10000000 picoseconds
Reliability is 255/255
Load is 1/255
Minimum MTU is 1500
Hop count is 0
Originating router is 58.1.1.5
Extended Community: SoO:58:58
iosv-5#sh ip eigrp vrf bbb topology 16.1.1.0/24
EIGRP-IPv4 VR(cisco) Topology Entry for AS(100)/ID(58.1.1.5)
Topology(base) TID(0) VRF(bbb)
EIGRP-IPv4(100): Topology base(0) entry for 16.1.1.0/24
State is Passive, Query origin flag is 1, 1 Successor(s), FD is 1310720
Descriptor Blocks:
1.1.1.1, from VPNv4 Sourced, Send flag is 0x0
Composite metric is (1310720/0), route is Internal (VPNv4 Sourced)
Vector metric:
Minimum bandwidth is 1000000 Kbit
Total delay is 10000000 picoseconds
Reliability is 255/255
Load is 1/255
Minimum MTU is 1500
Hop count is 0
Originating router is 16.1.1.1
Extended Community: SoO:16:16最下部、Extended CommunityにてSoOが付与されていることが確認できる。
確認2: show ip route eigrp
iosv-6#sh ip ro eigrp | b Gate
Gateway of last resort is not set
8.0.0.0/32 is subnetted, 1 subnets
D 8.8.8.8 [90/130816] via 68.1.1.8, 00:04:08, GigabitEthernet0/1
58.0.0.0/24 is subnetted, 1 subnets
D 58.1.1.0 [90/3072] via 68.1.1.8, 00:03:52, GigabitEthernet0/1
[90/3072] via 16.1.1.1, 00:03:52, GigabitEthernet0/0
88.0.0.0/32 is subnetted, 1 subnets
D 88.88.88.88 [90/130816] via 68.1.1.8, 00:04:08, GigabitEthernet0/1
iosv-8#sh ip ro eigrp | b Gate
Gateway of last resort is not set
6.0.0.0/32 is subnetted, 1 subnets
D 6.6.6.6 [90/130816] via 68.1.1.6, 00:05:47, GigabitEthernet0/1
16.0.0.0/24 is subnetted, 1 subnets
D 16.1.1.0 [90/3072] via 68.1.1.6, 00:05:20, GigabitEthernet0/1
[90/3072] via 58.1.1.5, 00:05:20, GigabitEthernet0/0
66.0.0.0/32 is subnetted, 1 subnets
D 66.66.66.66 [90/130816] via 68.1.1.6, 00:05:47, GigabitEthernet0/1SoOがそれぞれ異なる値で設定されているため、ルーティングテーブルに経路が載る。
設定2: 同じSoO
iosv-5(config)#int gi0/0
iosv-5(config-if)#no ip vrf sitemap SOO
*Sep 11 08:29:56.124: %DUAL-5-NBRCHANGE: EIGRP-IPv4 100: Neighbor 58.1.1.8 (GigabitEthernet0/0) is down: SoO changed
*Sep 11 08:29:58.138: %DUAL-5-NBRCHANGE: EIGRP-IPv4 100: Neighbor 58.1.1.8 (GigabitEthernet0/0) is up: new adjacency
iosv-5(config-if)#exit
iosv-5(config)#route-map SOO_2 permit 10
iosv-5(config-route-map)#set extcommunity soo 16:16
iosv-5(config-route-map)#int gi0/0
iosv-5(config-if)#ip vrf sitemap SOO_2確認1: show ip eigrp vrf topology
iosv-1#sh ip eigrp vrf bbb topo 58.1.1.0/24 | i Extend
Extended Community: SoO:16:16
iosv-5#sh ip eigrp vrf bbb topo 16.1.1.0/24 | i Extend
Extended Community: SoO:16:16確認2: show ip route eigrp
iosv-6#sh ip ro eigrp | b Gate
Gateway of last resort is not set
8.0.0.0/32 is subnetted, 1 subnets
D 8.8.8.8 [90/130816] via 68.1.1.8, 00:02:07, GigabitEthernet0/1
58.0.0.0/24 is subnetted, 1 subnets
D 58.1.1.0 [90/3072] via 68.1.1.8, 00:01:12, GigabitEthernet0/1
88.0.0.0/32 is subnetted, 1 subnets
D 88.88.88.88 [90/130816] via 68.1.1.8, 00:02:07, GigabitEthernet0/1
iosv-8#sh ip ro eigrp | b Gate
Gateway of last resort is not set
6.0.0.0/32 is subnetted, 1 subnets
D 6.6.6.6 [90/130816] via 68.1.1.6, 00:02:11, GigabitEthernet0/1
16.0.0.0/24 is subnetted, 1 subnets
D 16.1.1.0 [90/3072] via 68.1.1.6, 00:01:51, GigabitEthernet0/1
66.0.0.0/32 is subnetted, 1 subnets
D 66.66.66.66 [90/130816] via 68.1.1.6, 00:02:11, GigabitEthernet0/1SoOが同じなのでMPLS網側から経路を学習しなくなった。
自分メモ（BGP SoOとの違い）
※間違っている可能性有
・BGPのSoOとかなり挙動が違う
・そもそもEIGRPは別NW跨いだ時、両端が同じASでも無条件で経路を学習する（BGPの場合allowas-inが必要になる）
・なんなら以前BGPのSoOを検証したときは、マルチホーム環境でルーティングループが発生する際の解決策としてSoOを使っていたけど、今回は冗長化された経路（directly/via MPLS）の制御で使われているから用途が全然違う
参考
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