Just upgraded from 6.49.3 to 7.13
Home Router RB4011 becomes unreachable with “wrong” MTU size on L2TP over IPSEC connection to Mikrotik Gateway CCR1016.
After using the L2TP connection for ssh to a server and typing something on it the RB4011 becomes completely unresponsive. LEDs are on and are flickering but there is no way to connect , even not mac-telnet. Only a poweroff makes the 4011 working again. Reducing the MTU from 1450 to 1420 solves the problem. MTU 1450 and MRRU 1600 seems to work also.