Greetings - we have been having issues with CCRs (including a 1072) dropping all or part of the established PPPoE sessions, during which the CCR appears to stop responding to API/SSH (WebFig remains available but most sections are blank). We contacted Mikrotik with support files etc. and eventually we were told “our hardware is not up to your requirements”, yet our requirements are extremely “light” - PPPoE, NAT/route, rate-limit via simple queues (no OSPF etc.). We have a 1072 in our DC handling 9.5Gbps of traffic with NAT/route from 20 sub-networks, at CPU loads not exceeding 50%.
If you don’t find a fix, I’d suggest looking for an alternative vendor for PPPoE concentrator duties, as we are currently doing. This problem was first reported in 2009 (11 years ago!!) and still has not been fixed. We can reliably reproduce and trigger the problem (if we drop any downstream network segment e.g. reboot a switch or a PtP link), but no fix in sight:
http://forum.mikrotik.com/t/rb1000-closing-tens-of-pppoe-connections-at-once/33500/1
We have tried all sorts of fixes, including raising PPPoE timeout to allow sessions to “survive” a temporary break of a downstream link (e.g. switch reboot as mentioned), to no avail. The traffic from the session comes back, but then all traffic stops while sessions are dropped and re-established:
Above you can see when we reboot a switch, the traffic from ~400 clients drops out, then comes back as if nothing had happened (session timeout 300 seconds on both CCR and CPEs), then the drop takes place about 2 minutes later.
Good luck!