3Com S7902E, Configuration Manual

Page: 736 / 2621

1-25
The interval between hello packets sent by the DIS is 1/3 the hello interval set with the isis timer hello
command.
Specifying the IS-IS Hello Multiplier
If a neighbor receives no hello packets from the router within the advertised hold time, it considers the
router down and recalculates the routes. The hold time is the hello multiplier times the hello interval.
Follow these steps to specify the IS-IS hello multiplier:
To do… Use the command… Remarks
Enter system view system-view ––
Enter interface view
interface interface-type
interface-number
––
Specify the number of hello packets a
neighbor must miss before declaring
the router is down
isis timer holding-multiplier
value [ level-1 | level-2 ]
Optional
3 by default
On a broadcast link, Level-1 and Level-2 hello packets are advertised separately and therefore you
need to set a hello multiplier for each level. On a P2P link, Level-1 and Level-2 hello packets are
advertised in P2P hello packets, and you need not specify Level-1 or Level-2.
Configuring a DIS Priority for an Interface
On an IS-IS broadcast network, a router should be elected as the DIS at a routing level. You can specify
a DIS priority at a level for an interface. The greater the interface’s priority is, the more likely it becomes
the DIS. If multiple routers in the broadcast network have the same highest DIS priority, the router with
the highest MAC address becomes the DIS.
Follow these steps to specify a DIS priority for an interface:
To do… Use the command… Remarks
Enter system view system-view ––
Enter interface view
interface interface-type
interface-number
––
Specify a DIS priority for the
interface isis dis-priority value [ level-1
| level-2 ]
Optional
64 by default