Traffic Eng

Monitoring

To verify the TE tunnel's status, the monitor command can be used.

/interface/traffic-eng/monitor 0 
tunnel-id: 12 
primary-path-state: on-hold 
secondary-path-state: established 
secondary-path: static 
active-path: static 
active-lspid: 3 
active-label: 66 
explicit-route: "S:192.168.55.10/32,L:192.168.55.13/32,L:192.168.55.17/32" 
recorded-route: "192.168.55.13[66],192.168.55.17[59],192.168.55.18[3]" 
reserved-bandwidth: 5.0Mbps

Reoptimization

The path can be re-optimized manually by entering the command /interface/traffic-eng/reoptimize [id] (where [id] is an item number or interface name). It allows network administrators to reoptimize the LSPs that have been established based on changes in bandwidth, traffic, management policy, or other factors.

Let's say a TE tunnel chose another path after a link failure on the best path. You can verify optimization by looking at explicit-route or recorded-route values if the record-route parameter is enabled.

/interface/traffic-eng/monitor 0 
tunnel-id: 12 
primary-path-state: established 
primary-path: dyn 
secondary-path-state: not-necessary 
active-path: dyn
active-lspid: 1
active-label: 67 
explicit-route: "S:192.168.55.10/32,S:192.168.55.13/32,S:192.168.55.14/32, 
S:192.168.55.17/32,S:192.168.55.18/32" 
recorded-route: "192.168.55.13[67],192.168.55.17[60],192.168.55.18[3]" 
reserved-bandwidth: 5.0Mbps

Whenever the link comes back, the TE tunnel will use the same path even if it is not the best path (unless reoptimize-interval is configured). To fix it we can manually reoptimize the tunnel path.

/interface/traffic-eng/reoptimize 0

/interface/traffic-eng/monitor 0 
tunnel-id: 12 
primary-path-state: established 
primary-path: dyn 
secondary-path-state: not-necessary 
active-path: dyn
active-lspid: 2
active-label: 81 
explicit-route: "S:192.168.55.5/32,S:192.168.55.2/32,S:192.168.55.1/32" 
recorded-route: "192.168.55.2[81],192.168.55.1[3]" 
reserved-bandwidth: 5.0Mbps

Notice how explicit-route and recorded-route changed to a shorter path.