145
Step Command
Remarks
2.
Enter IS-IS view.
isis
[
process-id
] [
vpn-instance
vpn-instance-name
]
N/A
3.
Configure the SPF
calculation interval.
timer spf
maximum-interval
[
minimum-interval
[
incremental-interval
] ]
By default:
•
The maximum interval is 5
seconds.
•
The minimum interval is 50
milliseconds.
•
The incremental interval is
200 milliseconds.
Configuring convergence priorities for specific routes
A topology change causes IS-IS routing convergence. To improve convergence speed, you can assign
convergence priorities to IS-IS routes. Convergence priority levels are critical, high, medium, and low. The
higher the convergence priority, the faster the convergence speed.
By default, IS-IS host routes have medium convergence priority, and other IS-IS routes have low
convergence priority.
To assign convergence priorities to specific IS-IS routes:
Step Command
Remarks
1.
Enter system view.
system-view
N/A
2.
Enter IS-IS IPv4 unicast
address family view.
1.
isis
[
process-id
] [
vpn-instance
vpn-instance-name
]
2.
cost-style
{
wide
|
wide-compatible
}
3.
address-family ipv4
[
unicast
]
N/A
3.
Assign convergence priorities
to specific IS-IS routes.
priority
{
critical
|
high
|
medium
}
{
prefix-list
prefix-list-name
|
tag
tag-value
}
By default, IS-IS routes, except
IS-IS host routes, have the low
convergence priority.
Setting the LSDB overload bit
By setting the overload bit in sent LSPs, a router informs other routers of failures that make it unable to
select routes and forward packets.
When an IS-IS router cannot record the complete LSDB, for example, because of memory insufficiency,
it will calculate wrong routes. To make troubleshooting easier, temporarily isolate the router from the IS-IS
network by setting the overload bit.
To set the LSDB overload bit:
Step Command
Remarks
1.
Enter system view.
system-view
N/A
2.
Enter IS-IS view.
isis
[
process-id
] [
vpn-instance
vpn-instance-name
]
N/A
