I've got a 751G-2HnD running and connecting to the internet through a PPTP connection and it was all working fine. But then things stopped working, the connection was up and I was able to ping hosts through the ping tool, however the DNS server running on the Mikrotik was no longer responding to requests. I'm running 5.15 and with firmware 2.38. The DNS server is set to cache responses and forward requests to my upstream provider, the domain ports were open.
Restarting the DNS server on the Mikrotik got the DNS server working again. I would just get rid of the DNS server and had out my upstream DNS servers in DHCP leases, but I find resolution of local DNS names useful.
Are there know issues with the DNS server? Any suggestions?