Mikrotik /31 Issue
I was troubleshooting a network last week and came across a situation where I wanted to use /31 subnets on Mikrotik routers. I added the address like usual with the /31 mask and it took the configuration however the CPE was having issues getting out to the internet still.
I’ve used /31’s plenty of times on Cisco devices and the Mikrotik did take the /31 mask so I was a bit confused. Turns out Mikrotik does not actually support /31 subnets properly. The workaround for this issue was to set the ip address on the Mikrotik side as a /32 and set the ip address of the CPE as the “network” address.
Then things worked “properly”. Until Mikrotik comes out with support for /31’s, this is the easiest solution.