1 Networking Requirements
2 Procedure
- 2.1 Switch A
- 2.2 Switch B
- 2.3 Switch C
- 2.4 View IS-IS Route Table on Switch A
- 2.5 Configuring Switch B to Import Route between BGP and IS-IS
- 2.6 View IS-IS Route Table on Switch A

Networking Requirements

Figure 1. Configuration Example of Interaction Between IS-IS and BGP

Config Example of Interaction Between IS-IS and BGP.jpg

As shown in Figure 1, there are three switches (Switch A, Switch B and Switch C) in this sample network. IS-IS routing protocol runs between Switch A and Switch B, and EBGP routing protocol runs between Switch B and Switch C. To enable communication between Switch A and Switch C, you need to configure to redistribute IS-IS routes to BGP routes, and BGP routes to IS-IS routes on Switch B.

Follow the configuration roadmap below to complete the configuration:

Configure VLAN interface and IP address for each interface to make the network reachable.
Enable IS-IS on Switch A and Switch B, and enable EBGP on Switch B and Switch C.
On Switch B, configure route redistribution between route protocol IS-IS and BGP.

Procedure

Switch A

Step1 Configure VLAN interface.

admin@SwitchA# set vlans vlan-id 100 l3-interface vlan100
admin@SwitchA# set vlans vlan-id 1000 l3-interface vlan1000
admin@SwitchA# set interface gigabit-ethernet te-1/1/3 family ethernet-switching native-vlan-id 100
admin@SwitchA# set interface gigabit-ethernet te-1/1/1 family ethernet-switching native-vlan-id 1000
admin@SwitchA# set l3-interface vlan-interface vlan100 address 192.168.20.1 prefix-length 24
admin@SwitchA# set l3-interface vlan-interface vlan1000 address 192.168.1.6 prefix-length 24

Step2 Enable IS-IS for the network segment.

admin@SwitchA# set protocols isis area-tag instance1 network-entity 32.0001.0040.0220.0001.00
admin@SwitchA# set protocols isis area-tag instance1 interface vlan100 ipv4-routing
admin@SwitchA# set protocols isis area-tag instance1 interface vlan1000 ipv4-routing

Step3 Enable IP routing.

admin@SwitchA# set ip routing enable true

Step4 Commit the configuration.

Switch B

Step1 Configure VLAN interface.

Step2 Enable IS-IS for the specified network segment.

Step3 Configure EBGP connection between Switch B and Switch C.

Step4 Enable IP routing.

Step5 Commit the configuration.

Switch C

Step1 Configure VLAN interface.

Step2 Configure EBGP connection between Switch B and Switch C.

Step3 Enable IP routing.

Step4 Commit the configuration.

View IS-IS Route Table on Switch A

On Switch A, use command run show isis route to check IS-IS route table, the route 55.55.55.0/24 does not exist.

Configuring Switch B to Import Route between BGP and IS-IS

View IS-IS Route Table on Switch A

On Switch A, use command run show isis route to view IS-IS route table again, route 55.55.55.0/24 has been inserted to Switch A’s routing table with metric value 10. Switch A and Switch C can communicate with each other now.