141
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
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
must dynamically adjust the LSP packet size to fit the smallest interface MTU, which takes time and affects
other services.
To specify LSP lengths:
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
3.
Specify the maximum length
of generated Level-1 LSPs or
Level-2 LSPs.
lsp-length originate
size
[
level-1
|
level-2
]
By default, the maximum length
of generated Level-1 LSPs or
Level-2 LSPs is 1497 bytes.
4.
Specify the maximum length
of received LSPs.
lsp-length receive
size
By default, the maximum length
of received LSPs is 1497 bytes.
Enabling LSP flash flooding
Changed LSPs can trigger SPF recalculation. To advertise the changed LSPs before the router recalculates
routes for faster network convergence, enable LSP flash flooding.
To enable LSP flash flooding:
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
3.
Enable LSP flash
flooding.
flash-flood
[
flood-count
flooding-count
|
max-timer-interval
flooding-interval
| [
level-1 |
level-2
] ] *
By default, LSP flash
flooding is disabled.