Are there any specific GPO settings that need to be domne when deploying SEPM?

I seem to have one area of about 30 machines not getting updated by SEPM. They are all on a domain with appropriate Group policies. It is not a firewall issue, becasue I can bring another machine there and use the same ethernet cable from the failing machine and that works. Of course the situation gets stranger as no firewall policy is in place with/out GPO. Removing the machine off the domain allows me to get updates so my conclusion is that it has to be GPO related. Im pretty sure of this but I am not sure of what setting is preventing the communication. i wanted to know if anyone is aware or has had issues with GPOs and SEPM, besides the firwall policy.

Thanks,
Altria