vpn being blocked by microtik

forgive me if I am having a bonehead moment.

for years I have had no problem using the windows client to connect to several clients sites with simple PPTP to their Mikrotik. however recently Comcast has forced me to use their xfi gateway instead of my own modem. the xfi gateway is in bridge mode and everything seems great but if I try to connect to a MikroTik with PPTP i see the connection made in the log but then nothing. it all hangs.

If i take my MikroTik out of the way and connect directly to the xfi gateway it works.

it also works if I set up a client on the Mikrotik itself

so:

computer–>Mikrotik–>Surboard modem–>PPTP works

computer–>Mikrotik–>xfi gateway–>PPTP fails

Mikrotik–>xfi gateway–>PPTP works

i have fully reet the Mikrotik (ccr1009) with the simplest setup I could

DHCP Client (to grab public from comcast)
DHCP Server (to server my local lan)
local IP on my eth2 for dhcp local netwok
1 nat rule src–local subnet–masqerade


what am I missing?

uggg…I knew I was an idiot…4 days of fighting this and I found it an hour after posting.

pptp service port was disabled.

Who good that solved!