3com MSR 20-20 참조 매뉴얼

<Sysname> system-view

[Sysname] isis 1

[Sysname-isis-1] graceful-restart interval 120 

IS-IS view

None

Use the graceful-restart suppress-sa command to set the SA 
(Suppress-Advertisement) bit during restart.

Use the undo graceful-restart suppress-sa command to clear the SA bit 
during restart.

By default, the SA bit is cleared during restart.

Note that:

■

A router that starts at the first time does not maintain the forwarding state. For 
a router that restarts IS-IS, copies of LSPs generated by this router during the 
previous incarnation may still exist in the lSP databases of other routers in the 
network.

■

Copies of LSPs in the LSP databases in other routers which may look “newer” 
than LSPs generated by the restarting router after it initializes LSP fragment 
sequence numbers. This may result in temporary blackholes until subsequent 
LSPs with higher sequence numbers are regenerated.

■

These blackholes can be avoided if the neighbors suppress advertising the 
previous adjacencies to the restarting router until the latter has flooded LSPs 
with higher sequence numbers.

# Set the SA bit during Graceful Restart.

<Sysname> system-view

[Sysname] isis 1

[Sysname-isis-1] graceful-restart suppress-sa 

import-route { isis [ process-id ] | ospf [ process-id ] | rip [ process-id ] | bgp 
[ allow-ibgp ] | direct | static } [ cost cost | cost-type { external | internal } | [ level-1 
| level-1-2 | level-2 ] | route-policy route-policy-name | tag tag ] *

undo import-route { isis [ process-id ] | ospf [ process-id ] | rip [ process-id ] | bgp | 
direct | static }