Configuring Convergence Priorities For Specific Routes; Setting The Lsdb Overload Bit - HP FlexFabric 12900E Series Configuration Manual

network. By adjusting the SPF calculation interval, you can prevent bandwidth and router resources
from being over consumed due to frequent topology changes.
When network changes are not frequent, the minimum-interval is adopted. If network changes
become frequent, the SPF calculation interval is incremented by incremental-interval × 2
number of calculation times) each time a calculation occurs until the maximum-interval is reached.
To control SPF calculation interval:
Step
1. Enter system view.
2. Enter IS-IS view.
3. Configure
calculation interval.

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
1. Enter system view.
2. Enter IS-IS IPv4 unicast
address family view.
3. Assign
priorities to specific IS-IS
routes.

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.
Command
system-view
isis [ process-id ] [ vpn-instance
vpn-instance-name ]
timer
the SPF
[
[ incremental-interval ] ]
Command
system-view
a isis [ process-id ] [ vpn-instance
vpn-instance-name ]
b cost-style
wide-compatible }
c address-family ipv4 [ unicast ]
•
Method
prefix-priority { critical | high |
medium
convergence
prefix-list-name | tag tag-value }
•
Method
prefix-priority
route-policy-name
spf
maximum-interval
minimum-interval
{ wide
} { prefix-list
route-policy
152
n-2
(n is the
Remarks
N/A
N/A
By default:
•
The maximum interval is
5 seconds.
•
The minimum interval is
50 milliseconds.
•
The incremental interval
is 200 milliseconds.
Remarks
N/A
|
N/A
1:
By default, IS-IS routes,
except IS-IS host routes,
have the low convergence
2:
priority.