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7604 hang after using Null0 in static route

Hi,

using a 7604 router in MPLS environment with IOS 2.3 SR2A

10 VRF defined. Yesterday whe make a change in production to send a static route to null0 for a temporary time.

After the test, whe changed the static route pointing to null0 to the original route

ex :

Before the change

ip route vrf PROD 10.6.0.0 255.255.0.0 10.6.124.30

Everything works fine

Change :

ip route vrf PROD 10.6.0.0 255.255.0.0 Null0

We make this change to forbid access to 10.6.0.0 subnet

Everything works fine

Come back :

ip route vrf PROD 10.6.0.0 255.255.0.0 10.6.124.30

After this, the router goes down in rounting. Some subnet directly connected disapear, are not redistributed ...

We have to reload the router to work properly.

Any idea ????

Best regards

1 REPLY
Silver

Re: 7604 hang after using Null0 in static route

You can set up a default route that indicates that traffic that doesn't have a specific match in the routing table to a destination gets routed out site one to the internet. Also give the subnet value. This is the behavior that I would expect as the IOS was to use the default for recursive next hops, this would probably lead to routing loops when an interface went down. Please provide sh ip route command output.

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