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Enabling IS-IS
1. Enter system view.
system-view
N/A
2. Enable IS-IS and enter IS-IS
view.
isis
[ process-id ]
[
vpn-instance
vpn-instance-name ]
By default, IS-IS is disabled.
3. Assign a NET.
network-entity
net
By default, NET is not assigned.
4. Return to system view.
quit
N/A
5. Enter interface view.
interface
interface-type
interface-number
N/A
6. Enable IS-IS on the interface.
isis enable
[ process-id ]
By default, IS-IS is disabled.
Setting the IS level and circuit level
Follow these guidelines when you configure the IS level for routers in only one area:
Set the IS level of all routers to Level-1 or Level-2 rather than different levels because the
routers do not need to maintain two identical LSDBs.
Set the IS level to Level-2 on all routers in an IP network for good scalability.
For an interface of a Level-1 or Level-2 router, the circuit level can only be Level-1 or Level-2. For an
interface of a Level-1-2 router, the default circuit level is Level-1-2. If the router only needs to form
Level-1 or Level-2 neighbor relationships, set the circuit level for its interfaces to Level-1 or Level-2.
This will limit neighbor relationship establishment.
To configure the IS level and circuit level:
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 IS level.
is-level
{
level-1
|
level-1-2
|
level-2
}
By default, the IS level is Level-1-2.
4. Return to system view.
N/A
5. Enter interface view.
interface
interface-type
interface-number
N/A
6. Specify the circuit level.
isis circuit-level
[
level-1
|
level-1-2
|
level-2
]
By default, an interface can
establish either the Level-1 or
Level-2 adjacency.
Configuring P2P network type for an interface
Perform this task only for a broadcast network that has up to two attached routers.
Interfaces with different network types operate differently. For example, broadcast interfaces on a
network must elect the DIS and flood CSNP packets to synchronize the LSDBs. However, P2P
interfaces on a network do not need to elect the DIS, and have a different LSDB synchronization
mechanism.