12-16-2008 12:33 PM - edited 03-06-2019 03:00 AM
Dear friends,
I am running OSPF on Ten Gig interfaces between Core and Distribution switches.
I want Distribution 1 and Distribution 2 switch (redundant switches) to not be OSPF adjancent.
I wanted to know that if i apply the following commands, will it be ok.
router ospf 10
no passive-interface t2/3
no passive-interface t3/3
passive-interface default
T2/3 and T3/3 are Core-1 and Core-2 connecting interfaces. Will applying the command passive-interface default override the previous 2 "no passive-interface commands" or no??
Just wanted to double check this part.
Thanks a lot
Gautam
Solved! Go to Solution.
12-16-2008 12:40 PM
Gautam
No the passive interface default will not override the the no passive-interface commands. It makes the default behavior to become passive. But any interface configured with no passive-interface will become active.
HTH
Rick
12-16-2008 12:42 PM
hello Gautam,
you still need to add the network area commands for the interfaces of interest.
2) if the default becomes passive-interface you need no passive-interface for interfaces where you want OSPF hellos to be sent out so the more specific command applies:
no passive for interfaces t2/3 and t3/3 passive for all the other ones whose IP subnets match a network area command
Hope to help
Giuseppe
12-16-2008 12:43 PM
Gautam
Yes this should be fine. You can verify the interface settings once you have added this config -
http://www.cisco.com/en/US/docs/ios/12_0t/12_0t2/feature/guide/defint.html#wp10202
Edit - apologies i completely misread the question. Rick is correct - the passive-interface default will not override the previous no passive-interface commands. It will just make all other interfaces than t2/3 & t3/3 passive.
Jon
12-16-2008 12:40 PM
Gautam
No the passive interface default will not override the the no passive-interface commands. It makes the default behavior to become passive. But any interface configured with no passive-interface will become active.
HTH
Rick
12-16-2008 12:42 PM
hello Gautam,
you still need to add the network area commands for the interfaces of interest.
2) if the default becomes passive-interface you need no passive-interface for interfaces where you want OSPF hellos to be sent out so the more specific command applies:
no passive for interfaces t2/3 and t3/3 passive for all the other ones whose IP subnets match a network area command
Hope to help
Giuseppe
12-16-2008 12:43 PM
Gautam
Yes this should be fine. You can verify the interface settings once you have added this config -
http://www.cisco.com/en/US/docs/ios/12_0t/12_0t2/feature/guide/defint.html#wp10202
Edit - apologies i completely misread the question. Rick is correct - the passive-interface default will not override the previous no passive-interface commands. It will just make all other interfaces than t2/3 & t3/3 passive.
Jon
05-07-2012 10:45 AM
This not true. If you add passive interface default, it will wipe out other 'no passive-interface
r2#show run | be router ospf
router ospf 1
log-adjacency-changes
passive-interface default
no passive-interface Ethernet0/0
no passive-interface Ethernet1/0
network 2.2.2.2 0.0.0.0 area 0
network 10.1.12.0 0.0.0.255 area 0
network 10.1.23.0 0.0.0.255 area 0
!
r2#
r2#conf
r2#conf t
Enter configuration commands, one per line. End with CNTL/Z.
r2(config)#router ospf 1
r2(config-router)#pass
r2(config-router)#passive-interface default
r2(config-router)#end
r2#show run | be
00:01:46: %SYS-5-CONFIG_I: Configured from console by console
r2#show run | be router ospf
router ospf 1
log-adjacency-changes
passive-interface default
network 2.2.2.2 0.0.0.0 area 0
network 10.1.12.0 0.0.0.255 area 0
network 10.1.23.0 0.0.0.255 area 0
!
r2#sh ver
Cisco IOS Software, Solaris Software (UNIX-P-M), Version 12.2(33)SXI5, DEVELOPMENT TEST SOFTWARE
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2011 by Cisco Systems, Inc.
Compiled Thu 03-Feb-11 08:47 by prod_rel_team
r3#show run | section router ospf
router ospf 1
log-adjacency-changes
passive-interface default
no passive-interface Ethernet0/0
no passive-interface Ethernet1/0
network 3.3.3.3 0.0.0.0 area 0
network 10.1.23.0 0.0.0.255 area 0
network 10.1.34.0 0.0.0.255 area 0
r3#
r3#conf t
Enter configuration commands, one per line. End with CNTL/Z.
r3(config)#router ospf 1
r3(config-router)#pass
r3(config-router)#passive-interface default
r3(config-router)#do show run | sec router ospf
router ospf 1
log-adjacency-changes
passive-interface default
network 3.3.3.3 0.0.0.0 area 0
network 10.1.23.0 0.0.0.255 area 0
network 10.1.34.0 0.0.0.255 area 0
r3(config-router)#do sh ver
Cisco IOS Software, Solaris Software (UNIX-P-M), Version 12.4(15)T8, DEVELOPMENT TEST SOFTWARE
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2008 by Cisco Systems, Inc.
Compiled Wed 03-Dec-08 14:46 by prod_rel_team
05-07-2012 05:51 PM
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Posting
Just wanted to also confirm Chalermchai's post, i.e. sequence of these commands can matter.
On some version of 6500 IOS, I've found OSPF's passive-interface or no passive-interface only take if they are contrary to the current default setting.
e.g.
router ospf 1
passive-interface default
no passive-interface Ethernet0/0
no passive-interface Ethernet1/0
or
router ospf 1
no passive-interface default
passive-interface Ethernet0/0
passive-interface Ethernet1/0
are okay but
router ospf 1
!already no passive-interface default
no passive-interface Ethernet0/0
no passive-interface Ethernet1/0
passive-interface default
or
router ospf 1
!already passive-interface default
passive-interface Ethernet0/0
passive-interface Ethernet1/0
no passive-interface default
were not okay.
05-08-2012 06:30 AM
This is certainly an interesting and unexpected behavior. As I think about it I would certainly agree with Joseph's point that sometimes the order of commands can affect how things work. And in a sense it is logical that if you have an existing configuration and you change the default behavior of the routing protocol (from default not passive to default passive) that it might reset the existing config to conform to the new default behavior.
I wonder if this represents a change in behavior introduced at some release? I thought that I remembered having configured a routing protocol, added the passive-interface default and not having impacted the existing config.
HTH
Rick
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