HP 6125XLG - Page 156

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If such a change occurs frequently, excessive LSPs are generated, consuming a large amount of
router resources and bandwidth. To solve the problem, you can adjust the LSP generation interval.
When network changes are not frequent, the minimum-interval is adopted. If network changes
become frequent, the LSP generation interval is incremented by incremental-interval × 2
n-2
(n is the
number of calculation times) each time a generation occurs until the maximum-interval is reached.
To specify the LSP refresh interval and generation interval:
Ste
p
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
3. Specify the LSP refresh
interval.
timer lsp-refresh seconds
By default, the LSP refresh
interval is 900 seconds.
4. Specify the LSP
generation interval.
timer lsp-generation maximum-interval
[ minimum-interval
[ incremental-interval ] ] [ level-1 |
level-2 ]
By default:
• The maximum interval is
5 seconds.
• The minimum interval is
20 milliseconds.
• The incremental interval
is 200 milliseconds.
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 these LSPs to control the amount of LSPs on the network.
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:
Ste
p
Command Remarks
1. Enter system view.
system-view N/A
2. Enter interface view.
interface interface-type
interface-number
N/A
3. Specify the minimum
interval for sending LSPs
and the maximum LSP
number that can be sent at a
time.
isis timer lsp time [ count
count ]
By default, the minimum interval is
33 milliseconds, and the maximum
LSP number that can be sent at a
time is 5.
4. Specify the LSP
retransmission interval on a
P2P link.
isis timer retransmit seconds
By default, the LSP retransmission
interval on a P2P link is 5 seconds.
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 the area.
If the IS-IS routers have different interface MTUs, HP recommends configuring the maximum size of
generated LSP packets to be smaller than the smallest interface MTU in the area. Otherwise, the routers