9. Passive interface of EIGRP configuration experiment
1. Experimental Topology
2. Application of passive interface
Passive interface (passive interface) is generally used for optimization. For example, in our topology, R2 has a loopback lo0:2.2.2.2, so it is not necessary to send EIGRP message to lo0 port. When we enable lo0 passive interface under the EIGRP routing process, R2 will no longer send any EIGRP messages to lo0, but the route of lo0 will still be sent by R2.
3. Basic configuration
R2
Interface Loopback0
Ip address 2.2.2.2 255.255.255.0
Interface Serial0/1
Ip address 23.1.1.2 255.255.255.0
Router eigrp 90
Network 23.1.1.0 0.0.0.255
Network 2.2.2.0 0.0.0.255
No auto-summary
R3
Interface Serial0/1
Ip address 23.1.1.3 255.255.255.0
Router eigrp 90
Network 23.1.1.0 0.0.0.255
No auto-summary
4. Passive interface configuration
First use debug debugging to see how EIGRP messages are sent under normal conditions.
Enable passive interface on R2
Router eigrp 90
Passive-interface Loopback0
As can be seen from the figure, only s0 EIGRP 1 is sending and receiving EIGRP messages at this time, and loopback0 no longer sends and receives any LoopBack0 messages, but R3 can still receive LoopBack0 routes.
