Hi everybody,
in the last days I tried a test configuration before roll-out v4 upgrade to all my Mikrotik based network.
Well, on every single Routerboard upgraded from 3.24 to 4.5 I found the same bug on OSPF: "authentication" parameter under Routing-->OSPF-->Interfaces-->Interface that was initially set to "MD5" changed automatically to "none". This happened on 532, 532A, 600 and 433AH both on ethernet and wireless interfaces with OSPF on them.
Doing that, OSPF link went down: no more neighbors and devices where reachable only via MAC address.
Solution: under Routing-->OSPF-->Interfaces-->Interface add a new interface with the very same parameters of the original one, but with authentication=MD5. Doing so, the original ones switch to MD5 and OSPF is up and running again.
Below you'll find attached images of before and after.
Bye,
mattia