5. (Optional.) Configure
the T1 timer.
graceful-restart t1 seconds count
count
By default, the T1 timer is 3 seconds and can
expire 10 times.
6. (Optional.) Configure
the T2 timer.
graceful-restart t2 seconds By default, the T2 timer is 60 seconds.
7. (Optional.) Configure
the T3 timer.
graceful-restart t3 seconds By default, the T2 timer is 300 seconds.
Configuring BFD for IS-IS
BFD provides a single mechanism to quickly detect and monitor the connectivity of links between OSPF
neighbors, reducing network convergence time. For more information about BFD, see High Availability
Configuration Guide.
To configure BFD for IS-IS:
Ste
N/A
3. Enable IS-IS on an interface.
isis enable [ process-id ] N/A
4. Enable BFD on an IS-IS
interface.
isis bfd enable
By default, an IS-IS interface
is not enabled with BFD.
Configuring IS-IS FRR
A link or router failure on a path can cause packet loss and routing loop. These problems can continue
until IS-IS completes the routing convergence based on the new network topology. IS-IS FRR uses BFD to
detect failures and enables fast rerouting to minimize the impact of link or node failures.
Figure 36 Network diagram for IS-IS FRR
In Figure 36, after you enable FRR on Router B, IS-IS automatically calculates or designates a backup next
hop when a link failure is detected. In this way, packets are directed to the backup next hop to reduce
traffic recovery time. Meanwhile, IS-IS calculates the shortest path based on the new network topology,
and forwards packets over the path after network convergence.
You can either enable IS-IS FRR to calculate a backup next hop automatically, or designate a backup next
hop with a routing policy for routes matching specific criteria.
To Next Page
Loading...
