JUNOS_ip monitoring
CiscoでいうところのIP SLAでのオブジェクトトラッキング
まぁ、ダイナミック使えば終わるんだけど、案件によって使えなかったりする際には重宝する機能。
以下で検証
R1とR4でそれぞれ設定入れてみる。
まずはCisco
track 1 ip sla 1 reachability
ip route 0.0.0.0 0.0.0.0 172.16.4.1 track 1
ip route 0.0.0.0 0.0.0.0 172.16.3.254 100
!
ip sla 1
icmp-echo 1.1.1.1
frequency 5
ip sla schedule 1 life forever start-time now
!
通常時はR3経由で、1.1.1.1への到達性がなければR2経由に切り替え
通常時のshow ip route
R4#sho ip route static
S* 0.0.0.0/0 [1/0] via 172.16.4.1
R1の1.1.1.1を消す
R4#sho ip route static
S* 0.0.0.0/0 [100/0] via 172.16.3.254
これと同じ挙動をJUNOSで再現。
set services rpm probe MONITOR test ICMP-Check target address 1.1.1.5
set services rpm probe MONITOR test ICMP-Check probe-count 3
set services rpm probe MONITOR test ICMP-Check probe-interval 3
set services rpm probe MONITOR test ICMP-Check test-interval 3
set services rpm probe MONITOR test ICMP-Check thresholds successive-loss 3
set services rpm probe MONITOR test ICMP-Check thresholds total-loss 3
set services rpm probe MONITOR test ICMP-Check next-hop 172.16.2.254
set services ip-monitoring policy MON-policy match rpm-probe MONITOR
set services ip-monitoring policy MON-policy then preferred-route route 0.0.0.0/0 next-hop 172.16.1.254
set routing-options static route 0.0.0.0/0 next-hop 172.16.2.254
通常時はR3をnext-hopにし、1.1.1.5と疎通が取れない場合に、R2経由に切り替え。
通常時のshow route
admin@R1# run show route protocol static
0.0.0.0/0 *[Static/5] 00:50:02
> to 172.16.2.254 via ge-0/0/1.0
R4の1.1.1.5をDownさせる
admin@R1# run show route protocol static
0.0.0.0/0 *[Static/1] 00:00:46, metric2 0
> to 172.16.1.254 via ge-0/0/0.0
[Static/5] 00:51:55
> to 172.16.2.254 via ge-0/0/1.0