You don't by chance have the interface costs set to where multiple paths have the same cost to the destination do you? The TTL Exceeded and the extra hops you are seeing is because of a routing loop - A mikrotik in the path is removing the route to that destination IP address, but other routers still have it installed, is my bet (and what I've seen personally). When this is occurring I bet if you log into the X.X.214.74 router there will be no route to that destination IP/network installed, or it will be pointing to a 'wrong' destination.
I've had a bugger with 6.X on our network. It's to the point that I'm considering dropping all of our MT core routers. My bandaids thus far that seem to mitigate the OSPF issues we are having: Make sure there is no ECMP to a destination within the network. Installed a rb750 in a cold dark corner on our network, made it part of the ospf network and then put a script on it to reboot it every 3 minutes. -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Justin Marshall Sent: Wednesday, March 05, 2014 2:05 PM To: Mikrotik discussions Subject: [Mikrotik] OSPF Issue Hi, We are having an OSPF issue. At least i'm assuming it's an OSPF issue because there are no static routes involved. We have our core router (imagestream) connected via Fiber to a Mikrotik at Tower A, Which in turn is connected via 2 RB411AH's with Atheros AR922X's to a Mikrotik at Tower B. Every 500-1000 pings we are loosing pings to 1 of the IP addresses on a bridge interface on the Mikrotik at Tower B. When this happens I see an IP address that is bound to one of the interfaces on our imagestream, show up on an MTR like so... Host Loss% Snt Last Avg Best Wrst StDev 1. 10.192.172.1 0.0% 3642 0.7 0.4 0.4 27.1 1.0 2. x.x.99.1 0.3% 3642 0.8 0.6 0.5 36.5 1.2 3. x.x.214.74 0.0% 3642 9.7 0.7 0.6 33.4 1.3 x.x.36.209 4. x.x.214.66 0.0% 3642 8.0 10.3 0.7 75.1 9.1 x.x.99.1 5. x.x.213.1 0.2% 3642 32.7 26.1 0.8 288.3 21.3 x.x.36.209 This is how it should look: Host Loss% Snt Last Avg Best Wrst StDev 1. x.x.172.1 0.0% 4 0.8 0.9 0.5 1.4 0.4 2. x.x.99.1 0.0% 4 0.7 0.8 0.6 1.0 0.2 3. x.x.214.74 0.0% 4 1.2 1.1 0.7 1.7 0.4 4. x.x.214.66 0.0% 3 29.8 15.5 5.7 29.8 12.7 5. x.x.213.1 0.0% 3 15.3 14.4 13.8 15.3 0.8 Both Mikrotik's are on 6.7, running OSPF. What we can't figure out is why this x.x.36.209 keeps showing up in the route. While this is happening, pings come back as: TTL exceeded. Also we aren't loosing any pings to any other IP's on the Mikrotik in question at Tower B, nor are we loosing pings to any other IP addresses bound to that bridge interface. The IP that we are loosing pings to is a public IP vs the others being private and not being in the /routing ospf networks. This may or may not be relevant. There is also no NAT involved whatsoever. Thanks for any input anyone can provide. This is causing us REAL issues... [email protected] -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://mail.butchevans.com/pipermail/mikrotik/attachments/20140305/a0df3723 /attachment.html> _______________________________________________ Mikrotik mailing list [email protected] http://mail.butchevans.com/mailman/listinfo/mikrotik Visit http://blog.butchevans.com/ for tutorials related to Mikrotik RouterOS _______________________________________________ Mikrotik mailing list [email protected] http://mail.butchevans.com/mailman/listinfo/mikrotik Visit http://blog.butchevans.com/ for tutorials related to Mikrotik RouterOS
