Okay, I tried something else and it's getting even stranger yet. Previously, at Chuck's suggestion I added no ip split-horizon. However, I only added it to the redistributing router. That had interesting yet not entirely successful results.
Then, I added no ip split-horizon to the IGRP-only router, which makes no sense since in my configuration it is not advertising any routes. Strangely enough, this seemed to work for a bit until a routing loop developed. ;-) So, I added a distribute list to the IGRP-only router disallowing any outgoing routing updates. Things are now equally unpredictable but I'm seeing sometihng I didn't see before: I 172.16.20.0/28 [100/10476] via 172.16.20.1, 00:00:30, Serial1 C 172.16.20.0/24 is directly connected, Serial1 I 172.16.10.0/28 [100/8976] via 172.16.20.1, 00:00:30, Serial1 I 172.16.5.0/28 [100/8976] via 172.16.1.1, 00:00:30, Serial1 C 172.16.1.0/28 is directly connected, Serial1 See the 172.16.20.0/28 route? It doesn't exist! 172.16.20.0/24 is directly connected. For some reason, this router now thinks it's learning the /28 subnet of that network via IGRP, which it isn't. My guess is that it's taking the network from the secondary address and applying the mask of the primary address. Bizarre, and very undesirable! Now I'm back to where I was before. Tunnels, while being unwieldy and ugly, work. If a back-to-back frame relay connection is allowed then subinterfaces work equally well. It really seems that there ought to be another way to make this work so if anyone discovers the trick that I appear to be missing, please pass it along. I'm sure there is a key to this that I'm overlooking. Thanks, John the Bewildered ________________________________________________ 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=29607&t=29607 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]