I had to deal with this Exact problem last week. Never got EOIP to work,
Spent hours on it.
I had to use a "GRE Tunnel" Which is the same thing. And is only available
under RouterOS 5.x+. Came right up when EOIP wouldn't. I don't know how to
peg the problem. As PPTP, EOIP, GRE...etc All use the GRE protocol 47. So
you would think they all would show the same problem.
I never even attempted to contact comcast support as I wasn't about to
spend another 3 hours explaining my problem only for them to say they
aren't blocking anything and it must be my side..
(855) FLSPEED x106