I upgraded an RB1100 with an RB1100AHx2 which serves as my gateway router for about 10 other routers which are all linked together via OSPF. I exported and imported the file to make an exact copy but when I fired up that router all hell broke loose! We had to winbox into each of the connecting routers and connect through mac address and reboot the remotes to get them going again. Some of the routers required more than 1 reboot before they received any routes to the default gateway. They were showing the ospf was connected as either designed or backup router but were not getting any routes from the new router. Once I got them all up and running several of them were sending their traffic to the higher cost routers instead of the lower cost. But it was working so I left it alone until the middle of the night when I set a schedule to reboot all routers simultaenously and then all started working as expected.

This might be a bit of a vague question since you dont know my network layout but I'm wondering if there is an obvious reason for this. All routers are routerboard brand with 5.14 software. Any input would be great, thanks.

It might be related to som ospf bug. :

http://forum.mikrotik.com/viewtopic.php?f=14&t=34170