Migrating from explicit passive-interface to passive-interface default

[George Cussins]

                   Migrating from an explicit passive-interface configuration to a passive-interface default configuration followed by no-passive interface on interfaces where you want to get routing updates. How long do you have before neighbor is lost? You are not able to enter the no-passive statements until after the passive-interface default is coded. Is this possible without an outage i.e. to make this transition without loosing the neighbor? My thinking is that you would have to beat the OSPF dead timer sequence.

[Rolf Fischer]

A very fast way to apply such changes is to prepare a partial configuration file on a TFTP-server and then import it at one go:

R1#show run | section router

router ospf 1

router-id 1.1.1.1

!

R1#more tftp://192.168.2.2/OSPF.cfg

router ospf 1

passive-interface default

no passive-interface fa0/0

no passive-interface fa1/0

no passive-interface fa2/0

end

R1#copy tftp://192.168.2.2/OSPF.cfg running-config

Destination filename [running-config]?

Accessing tftp://192.168.2.2/OSPF.cfg...

Loading OSPF.cfg from 192.168.2.2 (via FastEthernet0/0): !

[OK - 131 bytes]

%SYS-5-CONFIG_I: Configured from tftp://192.168.2.2/OSPF.cfg by console

R1#show run | section router

router ospf 1

router-id 1.1.1.1

log-adjacency-changes

passive-interface default

no passive-interface FastEthernet0/0

no passive-interface FastEthernet1/0

no passive-interface FastEthernet2/0

If you don't have very aggressive OSPF timers, I wouldn't expect any problems.

HTH

Rolf

[Richard Burts]

I agree with Rolf that the quickest and most expedient way to get the change in is to put the changes into a file and tftp to the device. My impression is that you may still have a loss of neighbor relationship.

HTH

Rick