5.3 MPLS TE Explicit Paths• Once R5’s link is disabled R2’s tunnel interface goes down. From the above output we can see that there is a path calculation error, as R2 cannot reach the link between R5 and XR1. Even though R2 can still reach the Loopback of XR1, which is the tunnel destination, traffic cannot be routed over the tunnel since there is no valid path option. The result is that R2 and XR1 can still reach each other, but the end customers cannot.• To avoid this problem either Fast Reroute (FRR) Link or Node Protection can be configured to automatically heal around the broken link or router, or a lower priority dynamic path option can be configured. R2(config)#int tunnel0 R2(config-if)#tunnel mpls traffic-eng path-option 2 dynamic RP/0/0/CPU0:XR1(config)#interface tunnel-te0 RP/0/0/CPU0:XR1(config-if)#path-option 2 dynamic
5.4 MPLS TE Bandwidth Reservations 50 Mbps G0/0/0/0 E0/0 G0/0/0/0 E1/0 lo0 lo0 G0/0/0/3PE 35 Mbps PE75Mbps 30Mbps 30Mbps 75Mbpsvia RSVP G0/0/0/2 via RSVP E1/2.36 via RSVP via RSVP E0/0 MPLS TE E0/2.34 ISIS Level 2 E0/2.56 RSVP, Dynamic Tunnel option Autoroute Announce E0/1 75Mbps E1/2.45 75Mbps via RSVP via RSVP
5.5 MPLS TE Metric ManipulationWhen OSPF or IS-IS is used in the SP core for the purpose of MPLS TrafficEngineering, two different metrics are advertised for each link, the IGP metricand the TE metric. By default the TE metric is inherited from the IGP metric. Ifthe IGP metric is changed, i.e. the OSPF cost or the IS-IS metric, the TE metricwill likewise change. However, the TE metric can be manually changedseparately from the IGP metric. Additionally by default all MPLS TE tunnels willprefer to use the TE metric value for their dynamic path selection.This can be controlled globally or on a per-tunnel basis with the commandtunnel mpls trafficeng path-selection metric igp in regular IOS or path-selection metric igp in IOS XR at the tunnel interface level.The TE metrics can be verified by viewing the MPLS TE topology, as follows.
5.6 MPLS TE with Static Routing G0/0/0/0 E0/0 Static route to XR1 Static route to R2 over TE tunnel over TE tunnel G0/0/0/0 E1/0 lo0 lo0 G0/0/0/3PE PE E1/2.36 G0/0/0/2 E0/0 MPLS TE E0/2.34 ISIS Level 2 E0/2.56 RSVP, Dynamic Tunnel option Autoroute Announce E0/1 E1/2.45
5.6 MPLS TE with Static RoutingR2#show ip route 220.127.116.11Routing entry for 18.104.22.168/32 Known via "static", distance 1, metric 0 (connected) Routing Descriptor Blocks: * directly connected, via Tunnel0 Route metric is 0, traffic share count is 1RP/0/0/CPU0:XR1#show route 22.214.171.124Thu Jan 3 16:10:43.516 EETRouting entry for 126.96.36.199/32 Known via "static", distance 1, metric 0 (connected) Installed Jan 3 15:49:07.335 for 00:21:37 Routing Descriptor Blocks directly connected, via tunnel-te0 Route metric is 0 No advertising protos.
5.7 MPLS TE with Targeted LDP Adjacencies G0/0/0/0 E0/0 RSVP G0/0/0/0 E1/0 Static route via tunnel to XR1 MPLS TE Static route via tunnel to R2 G0/0/0/3 PEPE ldp ldp ldp E1/2.36 Target ldp G0/0/0/2 E0/0 Target ldp E0/2.34 E0/2.56 E0/1 E1/2.45 ldp
5.8 MPLS TE Fast Reroute G0/0/0/0 E0/0E1/0 MPLS TE G0/0/0/0 L3VPN lo0 RSVP G0/0/0/3 PE lo0PE Autoroute announce FRR lo0 G0/0/0/2 E1/2.36 BFD >1sec E0/0 E0/2.34 E0/2.56 FRR lo0 E0/1 BFD >1sec E1/2.45 Autoroute announce
5.10 Inter-Area MPLS TE with IS-IS IS-IS NET IS-IS NET G0/0/0/0 01.0000.0000.000Y.00 E0/000.0000.0000.000Y.00 Level-1 MPLS TE Level-1 G0/0/0/0E1/0 RSVP Autoroute G0/0/0/3 L1/L2 Level-2 E1/2.36 L1/L2 G0/0/0/2 E0/0 Level-2 E0/2.34 Level-2 E0/2.56 E0/1 E1/2.45 L1/L2 Level-2 L1/L2
5.11 Inter-AS MPLS TE IS-IS NET OSPF Static to R1 00.0000.0000.000Y.00 AREA 0 lo0 via tunnel G0/0/0/0 E0/0E1/0 Level-2 G0/0/0/0 Passive interface G0/0/0/3 MPLS TE PE autoroute E1/2.36 G0/0/0/2 E0/0 E0/2.34 E0/2.56 Level-2 E0/1 E1/2.45 MPLS TE, RSVP on transit int