reply to raytaylor
Re: Microtik and IPv6 Thanks for your reply
They will be ubnt rockets for the WDS backhauls so if the wireless link goes down, the ethernet will stay up. I am hoping it has some way of detecting that it cant talk to the next router in the loop and then cut the link.
I have seen a feature request in the ubnt forums that if a wireless link goes down, they want the rocket to cut the ethernet port also - i assume this is what you are talking about for the physical interface.
He said this was because he didnt want to wait for OSPF to detect the link was down and needed it to respond instantly, where as i dont mind if it goes down for 30 seconds while it waits for some sort of ping? to fail and then start using another path, while rechecking the link every minute or so to see if it is back up.
Cant seem to find any specific info on how this would work if the ethernet port stays up (to the radio) but the radio link goes down.
I use OSPF for failover for my two links to my upstream provider. One is a direct PTP shot which plugs into my core router, and the other is a shot to one of their other towers which runs over a VPN back to the same core router to make it look like both links are simple PTP shots.
I have the hello interval set to 1 second, and the router dead interval set to 5 seconds. That basically means that it will check the link every second to make sure it is still online, and if it doesn't respond for 5 seconds, it will failover to my other link.
I tested it down to 2 or 3 seconds, which worked, but caused some excessive flopping if I had any packet loss. 5 seconds has worked will for the last 2 years. You'll drop a few pings, but other than a little delay waiting for a page to load, the failover typically happens before most streaming video sites even run out of their buffer.