HP MSR Series Configuration Manual page 149

Each router needs to refresh LSPs generated by itself at a configurable interval and send them to
other routers to prevent valid routes from being aged out. A smaller refresh interval speeds up
network convergence but consumes more bandwidth.
When the network topology changes, for example, a neighbor is down or up, or the interface
metric, system ID, or area ID is changed, the router generates an LSP after a configurable interval.
If such a change occurs frequently, excessive LSPs are generated, consuming a large amount of
router resources and bandwidth. To resolve this issue, you can adjust the LSP generation interval.
To specify the LSP refresh interval and generation interval:
Step
1. Enter system view.
2. Enter IS-IS view.
3. Specify the LSP refresh
interval.
4. Specify the LSP
generation interval.
3. Specify LSP sending intervals
If a change occurs in the LSDB, IS-IS advertises the changed LSP to neighbors. You can specify the
minimum interval for sending such LSPs.
On a P2P link, IS-IS requires an advertised LSP be acknowledged. If no acknowledgement is
received within a configurable interval, IS-IS will retransmit the LSP.
To configure LSP sending intervals:
Step
1. Enter system view.
2. Enter interface view.
3. Specify the minimum
interval for sending LSPs
and the maximum LSP
number that can be sent at a
time.
4. Specify the LSP
retransmission interval on a
P2P link.
Specifying LSP lengths
IS-IS messages cannot be fragmented at the IP layer because they are directly encapsulated in frames.
IS-IS routers in an area must send LSPs smaller than the smallest interface MTU in this area.
Command
system-view
isis [ process-id ] [ vpn-instance
vpn-instance-name ]
timer lsp-refresh seconds
timer lsp-generation maximum-interval
[ initial-interval [ second-wait-interval ] ] [ level-1
| level-2 ]
Command
system-view
interface interface-type
interface-number
isis timer lsp time [ count
count ]
isis timer retransmit seconds
137
Remarks
N/A
N/A
Optional.
The default interval is
900 seconds.
Optional.
The default interval is
2 seconds.
Remarks
N/A
N/A
Optional.
By default, the minimum interval is
33 milliseconds, and the maximum
LSP number that can be sent at a
time is 5.
Optional.
5 seconds by default.
Configure a proper LSP
retransmission interval to avoid
unnecessary retransmissions.