As previously mentioned I don’t appear to have a Ethernet port flapping issue but what I did encounter on a ptp link using 5.5/5.4 was on the Ethernet side of PtP was partial loss of connectivity where I could not login with winbox but sometimes Mac-telnet in and now I have unchecked “default authenticate” on wireless which after two days has stopped this issue so far, all of this has me asking questions how robust is MT routerboards and can they be effected by connected devices and I have updated an old post about a laptop which will not allow any connected board to reboot, http://forum.mikrotik.com/t/router-411-rb711-433-will-not-reboot/43653/1