拡張tag

初期設定

全ルータでEIGRP起動

Before

設定

R7(config)#route-map MAP permit 10
R7(config-route-map)#match ip add prefix PRE
R7(config-route-map)#set tag 1.2.3.4      
R7(config-route-map)#exit
R7(config)#route-map MAP permit 20
R7(config-route-map)#exit
R7(config)#ip prefix PRE permit 150.1.9.9/32
R7(config)#router eigrp 100
R7(config-router)#distribute-list route-map MAP in

tag 1.2.3.4を付与するよう設定。

確認1

R7#sh run | s prefix|route-map|router eigrp
router eigrp 100
 distribute-list route-map MAP in 
 network 0.0.0.0
ip prefix-list PRE seq 5 permit 150.1.9.9/32
route-map MAP permit 10
 match ip address prefix-list PRE
 set tag 16909060
route-map MAP permit 20

R7#sh ip ro 150.1.9.9
<略>
  * 155.1.79.9, from 155.1.79.9, 00:03:53 ago, via GigabitEthernet0/2
      Route metric is 130816, traffic share count is 1
      Total delay is 5010 microseconds, minimum bandwidth is 1000000 Kbit
      Reliability 255/255, minimum MTU 1500 bytes
      Loading 1/255, Hops 1
      Route tag 16909060

tag1.2.3.4を付与したはずなのに16909060になっている。

確認2

R6(config)#route-map MAP deny 10
R6(config-route-map)#match tag 1.2.3.4
R6(config-route-map)#exit
R6(config)#route-map MAP permit 20
R6(config-route-map)#exit
R6(config)#router eigrp 100
R6(config-router)#distribute-list route-map MAP in

拡張tagを有効にしないまま拡張tagを使用したルートフィルタリングを行う。

R4#sh ip ro 150.1.9.9
% Subnet not in table

CLIの表示の問題なので、拡張tagでフィルタリングができる。

After

R7(config)#route-tag notation dotted-decimal
R7(config)#do sh run | s route-map|router eigrp
router eigrp 100
 distribute-list route-map MAP in 
 network 0.0.0.0
route-map MAP permit 10
 match ip address prefix-list PRE
 set tag 1.2.3.4
route-map MAP permit 20

R6#sh ip ro 150.1.9.9 
Routing entry for 150.1.9.9/32
<略>
  * 155.1.67.7, from 155.1.67.7, 00:01:59 ago, via GigabitEthernet0/1
      Route metric is 131072, traffic share count is 1
      Total delay is 5020 microseconds, minimum bandwidth is 1000000 Kbit
      Reliability 255/255, minimum MTU 1500 bytes
      Loading 1/255, Hops 2
      Route tag 16909060

route-tag notation dotted-decimalを有効にしたルータのみ拡張tagが正常に表示される。

参考

Chapter: EIGRP Route Tag Enhancements