R3303-HP HSR6800 Routers Layer 3 - IP Routing Configuration Guide

151
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 ] 1497 bytes by default.
4. Specify the maximum length
of received LSPs.
lsp-length receive size 1497 bytes by default.
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 ] ] *
Not enabled by
default.
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 ] ] *
Not enabled by default.
4. Configure a virtual system
ID.
virtual-system virtual-system-id Not configured by default.
Limiting LSP flooding
In well-connected ATM, FR and NBMA networks, many P2P links exist. Figure 47 shows a fully meshed
network, where Routers A, B, C and D run IS-IS. When Router A generates an LSP, it floods the LSP out
of GigabitEthernet 2/1/1, GigabitEthernet 2/1/2 and GigabitEthernet 2/1/3. After receiving the LSP
from GigabitEthernet 2/1/3, Router D floods it out of GigabitEthernet 2/1/1 and GigabitEthernet