From: Thomas Larus (tlarus@xxxxxxx)
Date: Mon Oct 15 2001 - 13:24:04 GMT-3
I know there has been a lot of discussion of this problem, as apparently there
is a bootcamp lab dealing with it, but I don't remember seeing an answer yet
that would work in my lab situation.
I have an isdn link acting as an alternative path to a FR link. ISDN and FR
links go between the same two routers. The FR link is in area 0, and the isdn
link is in area 1. I have tried having both in area 0 and have the isdn
link's area be a NSSA area. Still the 224.0.0.5 OSPF LSA multicast keeps
bring the isdn link up right after it went down. And the thing that brings it
up seems to be the very change in the OSPF link state database brought about
by the ISDN link going down.
I have DLSW going over this backbone, but that is not bringing up the link.
Both sides of the link are in the same BGP AS, so there's no BGP issue here.
I have tried getting ip ospf demand-circuit to work before in a much simpler
config, and no luck.
I can't turn area one into a stub area, can I, since I actually want to use
this isdn as a transit link in my backbone when the FR link drops? ---- I
just tried stub area and it did not do the trick.
I only have native isdn support on one side of the isdn link (I use an Adtran
TA on the other side), but sh ip ospf int shows that ip ospf demand-circuit is
working on both routers and that hellos are being suppressed, so the
non-native isdn router situation does not seem to be an issue. I just want
the darn isdn routes to stay in there. Perhaps I could nail the isdn routes
up there with a static route. That's the only thing that comes to mind right
now. I have done this with floating static routes, but I am not sure if that
goes well with the ip ospf demand-circuit feature.--- I just tried floating
static route, and that did not seem to do the trick. While I held back
sending this message a few minutes to try a couple more things, another two
posts went up about ospf demand circuit, but slightly different context-- IGRP
was bring up the poster's link.
Other than keeping the isdn link up all the time, the setup is working great.
You unplug FR, and isdn takes over.
Thanks in advance,
Thomas Larus
This archive was generated by hypermail 2.1.4 : Thu Jun 20 2002 - 22:33:19 GMT-3