144
Figure 38
Network diagram of a fully meshed network
To avoid this problem, you can add interfaces to a mesh group or block some interfaces.
•
An interface in a mesh group floods a received LSP only to interfaces not in the mesh group.
•
A blocked interface sends LSPs only after receiving LSP requests.
Before you configure this task, you must consider redundancy for interfaces in case LSP packets cannot
be flooded because of link failures.
To add an interface to a mesh group or block an interface:
Step Command
Remarks
1.
Enter system view.
system-view
N/A
2.
Enter interface view.
interface
interface-type
interface-number
N/A
3.
Add the interface to a mesh
group or block the interface.
•
Add the interface to a mesh
group:
isis mesh-group
mesh-group-number
•
Block the interface:
isis mesh-group mesh-blocked
Use either method.
By default, the interface does not
belong to any mesh group and is
not blocked.
The mesh group feature takes effect
only on P2P interfaces.
Controlling SPF calculation interval
Based on the LSDB, an IS-IS router uses the SPF algorithm to calculate the shortest path tree with itself
being the root, and uses the shortest path tree to determine the next hop to a destination network. By
adjusting the SPF calculation interval, you can prevent bandwidth and router resources from being over
consumed due to frequent topology changes.
When network changes are not frequent, the
minimum-interval
is adopted. If network changes become
frequent, the SPF calculation interval is incremented by
incremental-interval
× 2
n-2
(n is the number of
calculation times) each time a calculation occurs until the
maximum-interval
is reached.
To control SPF calculation interval:
Step Command
Remarks
1.
Enter system view.
system-view
N/A
Eth1/1
Eth1/2
Eth1/3
Eth1/1
Eth1/1
Eth1/2
Eth1/3
Eth1/1
Eth1/2
Eth1/3
Eth1/2
Eth1/3
Router A
Router B
Router C
Router D
