Configuration
To establish the desired state of the topology in Figure 8.1, the metric on the link between the P8
and P4
routers should be increased, as illustrated here:
- Increase the metric on the
P8
router toward theP4
router from10
to100
:P8
router isis IGP interface GigabitEthernet0/0/0/1 address-family ipv4 unicast metric 100
- Increase the metric on the
P4
router toward theP8
router from10
to100
.P4
router isis IGP interface GigabitEthernet0/0/0/1 address-family ipv4 unicast metric 100
At first glance, it may appear that establishing a TI-LFA backup path for the primary path from P2
to PE5
is not feasible if there is a failure on the link between P2
and P3
, or a failure of the P3
node.
However, this scenario and the verification in the next section provide an opportunity to understand why TI-LFA guarantees 100% backup path coverage whenever a post-convergence path is available after a failure.
...