168
Verifying the configuration
After Router A establishes adjacencies with Router B and Router C, they begin to exchange routing
information. Restart IS-IS on Router A, which enters the restart state and sends connection requests to its
neighbors through the GR mechanism to synchronize the LSDB. To display the IS-IS GR status on Router
A, use the display isis graceful-restart status command.
# Restart the IS-IS process on Router A.
<RouterA> reset isis all 1 graceful-restart
Reset IS-IS process? [Y/N]:y
# Check the IS-IS GR state on Router A.
<RouterA> display isis graceful-restart status
Restart information for IS-IS(1)
--------------------------------
Restart status: COMPLETE
Restart phase: Finish
Restart t1: 3, count 10; Restart t2: 60; Restart t3: 300
SA Bit: supported
Level-1 restart information
---------------------------
Total number of interfaces: 1
Number of waiting LSPs: 0
Level-2 restart information
---------------------------
Total number of interfaces: 1
Number of waiting LSPs: 0
BFD for IS-IS configuration example
Network requirements
• As shown in Figure 45, run IS-IS on Router A, Router B and Router C so that they can reach each
other at the network layer.
• After the link over which Router A and Router B communicate through the Layer 2 switch fails, BFD
can quickly detect the failure and notify IS-IS of the failure. Router A and Router B then communicate
through Router C.