My router stop

Hi every one

I have MK OS 3.22 it was working very good, but from 4 dayes it stops.
I check all the setting and nothing changed. I reformat the server and install it again
with out any rules Only ip’s and dns and routers, but the same problem.
I notice that when I disable the internal interface on MK my router works.
If I enabled it again my router stops.

Did any one have this problem before

Sounds like a hardware problem. What hardware are you using?