多くの場合、HSRPを構成する時用意するL3機器は2台だと思います。
今回は、同一グループ内に6台のルータを並べたらActive/Standby/Listenステータスはどうなるのか？
また、各ルータどのようなPacketを送受信するのか？ 普段2台のHello Packetしか意識しない場合、新たな
発見があるかも？！
構成図（HSRPの場合）
結果
| R1 | R2 | R3 | R4 | R5 | R6 | |
| state | State is Active | State is Standby | State is Listen | State is Listen | State is Listen | State is Listen |
| Active router の認識 |
Active router is local | Active router is R1 | Active router is R1 | Active router is R1 | Active router is R1 | Active router is R1 |
| Standby router の認識 |
Standby router is R2 | Standby router is local | Standby router is R2 | Standby router is R2 | Standby router is R2 | Standby router is R2 |
| HSRP Hello 224.0.0.2 |
〇 | 〇 | × | × | × | × |
| Advertise 224.0.0.2 |
× | 〇 | 〇 | 〇 | 〇 | 〇 |
-
- 3台目以降のルータは「State is Listen」になる。
- 全ルータ誰が「State is Active」で「State is Standby」かを知っています。
- Hello Packetを送信するのは、「State is Active」、「State is Standby」
- Advertise Packetを送信するのは、「State is Standby」、「State is Listen」
debug standby packets all
R1(debug抜粋)
IOU1#debug standby packets all
*Nov 18 00:03:29.731: HSRP: Et0/0 Interface adv in, Passive, active 0, passive 1, from 10.1.1.2
↑R2からAdvertise (224.0.0.2)をを受信
*Nov 18 00:03:30.206: HSRP: Et0/0 Grp 1 Hello out 10.1.1.1 Active pri 200 vIP 10.1.1.254
↑自身からHelloを送信
*Nov 18 00:03:30.370: HSRP: Et0/0 Grp 1 Hello in 10.1.1.2 Standby pri 190 vIP 10.1.1.254
↑R2からHelloを受信
*Nov 18 00:03:30.707: HSRP: Et0/0 Interface adv in, Passive, active 0, passive 1, from 10.1.1.4
↑R4からAdvertise (224.0.0.2)をを受信
*Nov 18 00:03:38.109: HSRP: Et0/0 Interface adv in, Passive, active 0, passive 1, from 10.1.1.5
↑R5からAdvertise (224.0.0.2)をを受信
*Nov 18 00:03:43.294: HSRP: Et0/0 Interface adv in, Passive, active 0, passive 1, from 10.1.1.3
↑R3からAdvertise (224.0.0.2)をを受信
*Nov 18 00:03:47.991: HSRP: Et0/0 Interface adv in, Passive, active 0, passive 1, from 10.1.1.6
↑R6からAdvertise (224.0.0.2)をを受信R2(debug抜粋)
IOU2#debug standby packets all
*Nov 18 00:05:32.504: HSRP: Et0/0 Grp 1 Hello out 10.1.1.2 Standby pri 190 vIP 10.1.1.254
↑自身からHelloを送信
*Nov 18 00:05:34.827: HSRP: Et0/0 Grp 1 Hello in 10.1.1.1 Active pri 200 vIP 10.1.1.254
↑R1からHelloを受信
*Nov 18 00:05:37.666: HSRP: Et0/0 Interface adv in, Passive, active 0, passive 1, from 10.1.1.6
↑R6からAdvertise (224.0.0.2)をを受信
*Nov 18 00:05:39.001: HSRP: Et0/0 Interface adv out, Passive, active 0 passive 1
↑Advertise (224.0.0.2)を送信
*Nov 18 00:05:54.108: HSRP: Et0/0 Interface adv in, Passive, active 0, passive 1, from 10.1.1.3
↑R3からAdvertise (224.0.0.2)をを受信
*Nov 18 00:05:55.242: HSRP: Et0/0 Interface adv in, Passive, active 0, passive 1, from 10.1.1.5
↑R5からAdvertise (224.0.0.2)をを受信
*Nov 18 00:05:55.400: HSRP: Et0/0 Interface adv in, Passive, active 0, passive 1, from 10.1.1.4
↑R4からAdvertise (224.0.0.2)をを受信R6(debug抜粋)
IOU6#debug standby packets all
*Nov 17 23:51:49.180: HSRP: Et0/0 Interface adv out, Passive, active 0 passive 1
↑Advertise (224.0.0.2)を送信
*Nov 17 23:51:49.311: HSRP: Et0/0 Grp 1 Hello in 10.1.1.2 Standby pri 190 vIP 10.1.1.254
↑R2からHelloを受信
*Nov 17 23:51:50.988: HSRP: Et0/0 Grp 1 Hello in 10.1.1.1 Active pri 200 vIP 10.1.1.254
↑R1からHelloを受信
*Nov 17 23:51:52.222: HSRP: Et0/0 Grp 1 Hello in 10.1.1.2 Standby pri 190 vIP 10.1.1.254
↑R2からHelloを受信
*Nov 17 23:51:53.918: HSRP: Et0/0 Grp 1 Hello in 10.1.1.1 Active pri 200 vIP 10.1.1.254
↑R1からHelloを受信
*Nov 17 23:51:54.613: HSRP: Et0/0 Interface adv in, Passive, active 0, passive 1, from 10.1.1.4
↑R4からAdvertise (224.0.0.2)をを受信
*Nov 17 23:52:02.664: HSRP: Et0/0 Interface adv in, Passive, active 0, passive 1, from 10.1.1.3
↑R3からAdvertise (224.0.0.2)をを受信
*Nov 17 23:52:06.502: HSRP: Et0/0 Interface adv in, Passive, active 0, passive 1, from 10.1.1.5
↑R5からAdvertise (224.0.0.2)をを受信
*Nov 17 23:52:08.192: HSRP: Et0/0 Interface adv in, Passive, active 0, passive 1, from 10.1.1.2
↑R2からAdvertise (224.0.0.2)をを受信
まとめ
- State is Active・・・R1
- State is Standby・・・R2
- State is Listen・・・R3～R6
- HSPR Hello Packetは、マルチキャスト224.0.0.2
- HSPR Advertise Packetは、マルチキャスト224.0.0.2
- State is Active / State is StandbyルータがHSPR Helloを送信
- 全ルータがState is Active / State is Standbyルータが送信するHSPR Helloを受信
- Advertise Packetを送信・・・R2～R6
- 全ルータがR2～R6が送信するAdvertise Packetを受信
