Lately there have been a few posts regarding redistribution issues between IGRP and OSPF. One in specific had the following scenario:
R1----(IGRP)-----R2------(OSPF)------R3 The R1-to-R2 link is 172.16.1.0/24 and the R2 to R3 link is 172.16.2.0/28. Same major network, different subnet masks. The issue is that we want R1 to see the 172.16.2.0/28 network, but R2 won't advertise a /28 subnet of 172.16 out an interface that has a /24 mask. One solution we came up with was to add a loopback interface to R2 and then assign a "dummy" OSPF area to it. This makes R2 an ABR. Then you can use the area range command to summarize the /28 into a /24 and it can then be redistributed into IGRP. Notice that this allows R1 to see 172.16.2.0/24, not the /28. Another method we discovered this morning was to use a tunnel instead. Create a tunnel between R1 and R2 and give it a /28 mask, let's say 172.16.3.0/28. This alone will cause R2 to advertise 172.16.2.0/28 to R1. Now, to complete end-to-end connectivity you need to either add the tunnel endpoint on R2 to the OSPF process or redistribute connected on R2. This allows R3 to see the tunnel. You now have end-to-end connectivity without the need to add a new "dummy" OSPF area. Do any of you have any other ideas? We've tried using secondary IP addresses but have yet to make it work trying a few different methods. Regards, John ________________________________________________ Get your own "800" number Voicemail, fax, email, and a lot more http://www.ureach.com/reg/tag Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=28567&t=28567 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
