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Auto-add of sub-interfaces as "no passive-interface" in ospf


Good day. I've been having a problem with my cisco routers (7600s) where sub-interfaces that we create for ldp tunnels are added automatically to the main ospf process as no passive when created. In order, here is how to reproduce the issue:

- Configure ospf process as "passive-interface default"

- Configure interfaces that have to be active as "no passive-interface blah"

- ospf works as expected.

- Create new sub- interface somewhere with encapsulation on a certain vlan for xconnect.

- New sub-interface gets added as "no passive-interface" in main ospf process.

- When adding a new port-channel interface, behavior is the same.

Is that normal for cisco, should I continue removing sub-interfaces manually every time from the ospf process?

I'll be happy to provide any additional information if needed.


4 Replies 4

Giuseppe Larosa
Hall of Fame Master Hall of Fame Master
Hall of Fame Master

Hello Philippe,

I had the same experience with IS-IS  on C7600 with 12.2(18)SXF with a previous customer

In our case interfaces associated to a VRF were advertised in global routing table!

We removed passive-interface default on all nodes

I personally consider a behaviour like the one I have described  a SW bug and yours looks like similar

Hope to help


It seems like the general consensus that this is in fact a sw bug. I'll wait to see if anybody else has another solution before letting is go. The oly problem that this causes me is the addition of sub-ifs in ospf, which cannot do any real harm since they have no ip address.

Thanks for replying.

Cisco Employee
Cisco Employee

This is CSCse64565.

Alessio Andreoli
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