Configuring Spf Parameters - HP MSR Series Configuration Manual

Limiting LSP flooding
In well-connected ATM, FR and NBMA networks, many P2P links exist.
network, where Routers A, B, C and D run IS-IS. When Router A generates an LSP, it floods the LSP out
of Ethernet 1/1, Ethernet 1/2 and Ethernet 1/3. After receiving the LSP from Ethernet 1/3, Router D
floods it out of Ethernet 1/1 and Ethernet 1/2 to Router B and Router C. However, Router B and Router
C have already received the LSP from Router A. LSP flooding consumes extra bandwidth.
Figure 41 Network diagram of a fully meshed network
Router A
Eth1/1
Eth1/2
Eth1/3
Eth1/1
Eth1/2
Eth1/3
Router B
To avoid this, configure some interfaces as a mesh group, configure the blocked interfaces, or both.
After receiving an LSP, a member interface in a mesh group floods it out of the interfaces that do not
•
belong to the mesh group.
If an interface is blocked, it does not send LSPs unless the neighbor sends LSP requests to it.
•
Before you configure this task, you must consider redundancy for interfaces in case that LSP packets
cannot be flooded due to link failures.
To add an interface into a mesh group and block an interface:
Step
1. Enter system view.
2. Enter interface view.
3. Add the interface to a mesh
group, or block the interface.

Configuring SPF parameters

When the LSDB changes on a router, a route calculation starts. Frequent route calculations consume a lot
of system resources. You can set an appropriate interval for SPF calculations to improve efficiency.
To configure the SPF parameters:
Router D
Eth1/3
Eth1/2
Eth1/1
Eth1/1
Eth1/2
Eth1/3
Router C
Command
system-view
interface interface-type
interface-number
•
Add the interface to a mesh
group:
isis mesh-group
mesh-group-number
•
Block the interface:
isis mesh-group mesh-blocked
139
Figure 41 shows a fully meshed
Remarks
N/A
N/A
Use either method.
By default, the interface neither
belongs to any mesh group nor is it
blocked.
The mesh group feature takes effect
only on P2P interfaces.