I opened the Bug (MR) today.. Hope to have some resolution soon.. Good catch.. -M |-----Original Message----- |From: owner-usr-tc@lists.xmission.com |[mailto:owner-usr-tc@lists.xmission.com]On Behalf Of Mike Andrews |Sent: Tuesday, November 16, 1999 11:43 AM |To: usr-tc@lists.xmission.com |Subject: Re: (usr-tc) Continuing OSPF problems | | |On Tue, 16 Nov 1999, Brian wrote: | |> If I remember right it doesn't work like that. When you have a DR and a |> BDR, and you reboot the DR, yes the BDR becomes the DR. But |then when the |> "old" DR comes back up it does not become BDR. You have to reboot your |> other box (the original BDR , now DR) for this too happen. In other |> words, the cluenote I remember is "2 reboots are necessary for a |> re-election of OSPF DR/BDR". | |Turns out that it really doesn't matter who the DR/BDR is, or what the RFC |says about LSAs or floods :) | |The real problem is that the ARC is letting less specific routes override |more specific routes, and thus confusing itself about its own netmask. |That's apparently why communication fails with the new DR: | | |> > fra-ts2> list ip route |> > |> > IP ROUTES |> > Destination Prot NextHop Metric Interface |> > 0.0.0.0/0 NetMgr 206.240.130.1 1 eth:1 |> > 127.0.0.1/H LOCAL 127.0.0.1 1 loopback |> > 206.240.130.0/23 LOCAL 206.240.130.1 1 eth:1 |> > 206.240.130.14/H LOCAL 206.240.130.14 1 eth:1 |> > |> > This points out a problem I've brought up before. The subnet |mask on this |> > LAN should be /25, not /23. There is a /23 route being |advertised by the |> > Cisco that points at fra1's Null0 though (for BGP4 purposes) |and this is |> > somehow getting confused with the local netmask set on the eth:1 |> > interface, which is set correctly: |> |> Ok, fra1 is that your border? Are you injecting static routes into the |> IGP at all? I use tiedowns for my BGP routes as well.........you want to |> set these with a HIGH administrative weight, of like 250 though, so they |> don't get used. Do you have a weight set on them? | |Yeah, fra1 is the border (3620). The null0 tiedown routes have a "250" |distance metric on the end (used to be 10 til last night), and those |routes are getting injected into OSPF. The ARC still uses them whether |the metric is 10 or 250... it seems to ignore the metric. | |The only way I was able to make things sane was to stop the tiedowns from |getting injected into OSPF at all. I haven't yet figured out how to stop |just those routes from getting injected without shutting down |redistribution of ALL static routes. (Fortunately there aren't many other |static routes, so for now, this is what I've done.) I had tried various |combinations of distribute-list on the Cisco, as well as receivepolicy on |the ARC, and didn't have much luck. I'm sure there's a better way to do |it though. :) | |The screwed up netmask caused by this is *definitely* what's making it |stick in ExStart. I did find a workaround that did NOT require rebooting, |finally: | | reconfig ip network ip addr 206.240.130.14/25 (to fix the mask) | disable ospf | enable ospf | |and voila, things start working again. Of course the netmask goes back to |the wrong thing immediately after this, if you haven't stopped the |tiedowns from getting injected into OSPF... | | |> Also, using null0 as a tiedown used to be slow switched, so people used |> loopbacks, but I think now in later ios's this is not the case, and both |> can be used, but if you are running an older version you may want to |> consider that. | |It's 11.3(11a)T1... about 2 months old. | | |Mike Andrews (MA12) * mandrews@dcr.net * http://www.bit0.com/ |VP, sysadmin, & network guy, Digital Crescent Inc, Frankfort KY |Internet services for Frankfort, Lawrenceburg, Owenton, & Shelbyville |"With sufficient thrust, pigs fly just fine." -- RFC 1925 | | | | |- | To unsubscribe to usr-tc, send an email to "majordomo@xmission.com" | with "unsubscribe usr-tc" in the body of the message. | For information on digests or retrieving files and old messages send | "help" to the same address. Do not use quotes in your message. | - To unsubscribe to usr-tc, send an email to "majordomo@xmission.com" with "unsubscribe usr-tc" in the body of the message. For information on digests or retrieving files and old messages send "help" to the same address. Do not use quotes in your message.