Getting error message "%CLNS: Duplicate system ID configured in ip vrf <default> with router isis null" when configuring isis in 2900 router

[tu2pel]

Trying to apply  this config  to a 2900 router and getting this error message.

CMNTS3(config)#router isis Name

CMNTS3(config-router)#net <tag>

%CLNS: Duplicate system ID configured in ip vrf <default> with router isis null

CMNTS3(config-router)#

This works ok in in a 2800 router using 12.4(25d) spservices IOS

Not working on 2911 using 15.2(3)T2 ipbase image.

[Peter Paluch]

Hello,

Is there already a different IS-IS instance running on your router?

Ordinarily, IS-IS is configured in router isis mode without any instance name. You, however, are configuring your IS-IS in router isis Name mode. Do you have any particular need to configure the IS-IS instance using the Name tag? Can you try configuring it without the Name argument?

Best regards,

Peter

[tu2pel]

Peter,

Thanks for your reply.

Below is the config that we have on the 2800 router which is working fine. Only when we apply the same config on the 2900 that we get the error message.

router iso-igrp

net

redistribute isis

redistribute isis

redistribute isis

!

router isis

net

redistribute iso-igrp

!

router isis

net

is-type level-1

redistribute iso-igrp

!

router isis

net

is-type level-1

redistribute iso-igrp

[Peter Paluch]

Hello,

Interesting. After googling for this message, I got inconclusive results.

As a workaround, the only recommendation I can currently give it to use a different SystemID in the router iso-igrp process and a different SystemID in the router isis process. Can you try this out?

Some posts hint on the fact that this may be related to IS-IS Multiarea support which is not available in your IOS version. The latest IOS versions for 2911 that supported IS-IS Multiarea are 15.1(3)T or 15.1(4)M3. Perhaps you could try to downgrade your IOS to one of these versions and see if it helped.

Best regards,

Peter