Are the Ciscos sending the default route via BGP or OSPF? If via BGP, make sure you have Redistribute Default Route set in OSPF. Make sure you don't have a static default route anywhere either.
On Fri, Dec 9, 2011 at 3:21 PM, Craig Baird <[email protected]> wrote: > I've got a very weird situation that has come up lately. Wondering if > anyone has any ideas. I've got two connections out to the Internet that > enter my network in two different locations. Upstream ISP is the same on > both connections. We run BGP with them via two Cisco edge routers. They > send us a default route, which I'm injecting into OSPF at both locations. > > Now here's the weird part. If I lose BGP for connection A, every Mikrotik > V4 or V5 box in my network loses its default route completely. In contrast, > all my V3 or V2.9 (yes, I still have some of those) routers install the new > default route in the routing table, and off they go without so much as a > blink. If I do a 'routing ospf lsa print', the LSA for the new default is > there. But it never gets installed in the routing table. In order to get > these V4 and V5 routers to pick up the default, all I have to do is make a > change to OSPF somewhere on the network. I can make that change anywhere on > the network. It doesn't have to be on one of the V4 or V5 routers. Any > simple change will suddenly make these routers pick up the new default. > > To make it even stranger, this problem doesn't happen in reverse. If I lose > BGP for connection B, the default route for connection A propagates to all > routers in the network and everything is fine. > > I've been googling on this and found a few similar posts on the MT forum, > but nothing where MT has ever acknowledged that it's a bug. It sure looks > like one to me though, since it only affects V4 and V5 routers. I have a > difficult time believing that such a bug could exist through an entire > release's life cycle and well into the next without being fixed. > > Does anyone have any insight on this? > > Craig > > > _______________________________________________ > Mikrotik mailing list > [email protected] > http://www.butchevans.com/mailman/listinfo/mikrotik > > Visit http://blog.butchevans.com/ for tutorials related to Mikrotik RouterOS _______________________________________________ Mikrotik mailing list [email protected] http://www.butchevans.com/mailman/listinfo/mikrotik Visit http://blog.butchevans.com/ for tutorials related to Mikrotik RouterOS
