Change Totally Stub to NSSA no-summary in Routed Access Layer Design

lomonaco · ‎05-15-2009

Hi guys,

I'm using the document High Availability Campus Network Design Routed Access Layer using EIGRP or OSPF

to design my network...

Here the link...

http://www.cisco.com/application/pdf/en/us/guest/netsol/ns432/c649/ccmigration_09186a00805fccbf.pdf

Anybody see problems if I change the Totally Stub Areas to NSSA Areas to permite redistribute external OSPF networks in the NSSA Areas in the future..

Basically, I wanna change

area XXX stub no-summary

to

area XXX nssa no-redistribution no-summary

I think both are in the best practices, I just wanna confirm that...

Thanks in Advanced

My Best Regards,

Andre Lomonaco

Giuseppe Larosa · ‎05-15-2009

Hello Andre,

you should be fine.

My only doubt is that you may need also

area XXX nssa default-information-

originate

(Optional) Used to generate a Type 7 default into the NSSA area. This keyword takes effect only on the NSSA ABR or the NSSA Autonomous System Boundary Router (ASBR).

on the NSSA ABR(s) to have a default route pointing to core.

I mean ABR generates an 0 IA 0.0.0.0/0 for a stub area automatically for an NSSA you may need to add this option.

see

http://www.cisco.com/en/US/docs/ios/iproute/command/reference/irp_osp1.html#wp1011294

Hope to help

Giuseppe

jgreenwoodii · ‎05-15-2009

I agree with Guiseppe that you should be fine. He is using the Totally NSSA so a default route will be generated automatically. The "area XXX nssa default-information-originate" is only used for NSSA as noted by Guiseppe. I would also note that you will not see any redistributed routes in your Totally NSSA with the "no-redistribution" only command Type 7 LSA's will be seen along with the default route will only be seen in your area.

HTH

Jonathan