website pop up marketing passive-interface
Cisco CCNA | CCNP Certification Training Site. Cisco tips and tools for exam success. logo video

passive-interface

Printer-Friendly Format

Command

Passive-Interface Default

Use

This command prevents EIGRP from forming adjacencies on specified interfaces on the router. Using no passive-interface default will allow EIGRP communication.

Syntax

Router(config-router)#passive-interface <interface>

Example

In this example, we will use passive-interface default to block all EIGRP adjacencies. Then we will allow communication through R2's Fa0/0


R2(config)#do show ip route eigrp
1.0.0.0/32 is subnetted, 3 subnets
D 1.1.1.1 [90/156160] via 10.1.1.1, 00:49:20, FastEthernet0/0
D 1.3.3.3 [90/156160] via 10.1.1.1, 00:49:20, FastEthernet0/0
D 1.2.2.2 [90/156160] via 10.1.1.1, 00:49:20, FastEthernet0/0
192.168.13.0/30 is subnetted, 1 subnets
D 192.168.13.0 [90/2172416] via 10.2.2.3, 00:49:22, FastEthernet1/0
[90/2172416] via 10.1.1.1, 00:49:22, FastEthernet0/0
33.0.0.0/32 is subnetted, 1 subnets
D 33.33.33.33 [90/156160] via 10.2.2.3, 00:49:22, FastEthernet1/0
3.0.0.0/32 is subnetted, 1 subnets
D 3.3.3.3 [90/156160] via 10.2.2.3, 00:49:22, FastEthernet1/0
111.0.0.0/32 is subnetted, 1 subnets
D 111.111.111.111 [90/156160] via 10.1.1.1, 00:49:20, FastEthernet0/0
10.0.0.0/24 is subnetted, 3 subnets
D 10.4.4.0 [90/2172416] via 10.2.2.3, 00:50:57, FastEthernet1/0
[90/2172416] via 10.1.1.1, 00:50:57, FastEthernet0/0
11.0.0.0/32 is subnetted, 1 subnets
D 11.11.11.11 [90/156160] via 10.1.1.1, 00:49:20, FastEthernet0/0
133.133.0.0/32 is subnetted, 1 subnets
D 133.133.133.133 [90/156160] via 10.2.2.3, 00:49:22, FastEthernet1/0


Here we enable passive-interface default on R2.

R2(config)#router eigrp 100
R2(config-router)#passive-interface default
R2(config-router)#
*Mar 1 01:06:46.775: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 100: Neighbor 10.1.1.1 (FastEthernet0/0) is down: interface passive
*Mar 1 01:06:46.799: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 100: Neighbor 10.2.2.3 (FastEthernet1/0) is down: interface passive
R2(config-router)#


We can see there are no longer any EIGRP routes on R2.

R2(config-router)#do show ip route eigrp

R2(config-router)#

Now we will use no passive-interface fa0/0 to allow communication through R2's Fa0/0

R2(config)#router eigrp 100
R2(config-router)#no passive-interface fa0/0
R2(config-router)#
*Mar 1 01:07:55.815: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 100: Neighbor 10.1.1.1 (FastEthernet0/0) is up: new adjacency
R2(config-router)#

After that, we have routes coming in from Fa0/0 but not any other interface.

R2(config)#do show ip route eigrp
1.0.0.0/32 is subnetted, 3 subnets
D 1.1.1.1 [90/156160] via 10.1.1.1, 00:01:06, FastEthernet0/0
D 1.3.3.3 [90/156160] via 10.1.1.1, 00:01:06, FastEthernet0/0
D 1.2.2.2 [90/156160] via 10.1.1.1, 00:01:06, FastEthernet0/0
192.168.13.0/30 is subnetted, 1 subnets
D 192.168.13.0 [90/2172416] via 10.1.1.1, 00:01:06, FastEthernet0/0
33.0.0.0/32 is subnetted, 1 subnets
D 33.33.33.33 [90/2300416] via 10.1.1.1, 00:01:06, FastEthernet0/0
3.0.0.0/32 is subnetted, 1 subnets
D 3.3.3.3 [90/2300416] via 10.1.1.1, 00:01:06, FastEthernet0/0
111.0.0.0/32 is subnetted, 1 subnets
D 111.111.111.111 [90/156160] via 10.1.1.1, 00:01:06, FastEthernet0/0
10.0.0.0/24 is subnetted, 3 subnets
D 10.4.4.0 [90/2172416] via 10.1.1.1, 00:01:06, FastEthernet0/0
11.0.0.0/32 is subnetted, 1 subnets
D 11.11.11.11 [90/156160] via 10.1.1.1, 00:01:06, FastEthernet0/0
133.133.0.0/32 is subnetted, 1 subnets
D 133.133.133.133 [90/2300416] via 10.1.1.1, 00:01:06, FastEthernet0/0



Back to commands department




Printer-Friendly Format

This site and/or material is not sponsored by, endorsed by, or affiliated with Cisco Systems, Inc. and/or its affiliates. Cisco®, Cisco Systems®, CCDA™, CCNA™, CCDP™, CCNP™, CCIE™, or CCSI™ are trademarks or registered trademarks of Cisco Systems, Inc. and/or its affiliates in the United States and certain other countries.

Home | Search | Contact Us | Tell a Friend | Text Size

2006-2013 HowtoNetwork.net All Rights Reserved. Reproduction without permission prohibited.
Reality Press, Midsummer Court, 314 Midsummer Blvd.,Milton Keynes, MK92UB, UK

This site is powered by MemberGate Membership Site Software