Hello everyone! Hope you can help us, and I want to check if I'm wrong or the RouterOS has a bug (currently using 6.42.12 long-term)
Our topology consists in like 350 routers deployed around the country, and it's working with OSPF (multitarea) + BGP; everything was going fine, except when we got the requirement to allow JumboFrames at our network, so we were moving everything to 10.000 (using CCR only); and it was fine, but... a few weeks ago most routers go down suddenly, we've checked everything and those routers are affected at layer2 (which means, no Mac-telnet, no RoMON, no ARP, no LLDP), and everything is solved when the router is rebooted (manually or via watchdog).
After a few weeks of testing some scenarios we discovered that all of the affected routers are configured with the default L2MTU (1580 to 1600) and those are connected to a new router with a L2MTU (10000) at the interface and the trigger was a LSA flooding (after a convergence in a path inside the area); the router went down and the watchdog rebooted it.
Do you know if a L2MTU mismatch can cause this issue???