HP VPN Firewall Appliances Network Management Configuration Guide
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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 this 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:
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 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:
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. 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.
Enabling LSP fragment extension
After LSP fragment extension is enabled for an IS-IS process, the MTUs of all the interfaces running the
IS-IS process must not be less than 512. Otherwise, LSP fragment extension will not take effect.
At least one virtual system must be configured for the router to generate extended LSP fragments. An IS-IS
process allows a maximum of 50 virtual systems.
To enable LSP fragment extension:
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. Enable LSP fragment
extension and specify the
working mode.
lsp-fragments-extend [ [ level-1 | level-1-2 |
level-2 ] | [ mode-1 | mode-2 ] ] *
By default, this feature is
disabled.
4. Configure a virtual system
ID.
virtual-system virtual-system-id
By default, no virtual system
ID is configured.