Comcast SMC Modem blocking PPTP
Hi,
We have a Comcast Business SMC Networks modem hardware version 1B and are having problems getting PPTP to pass through. I have called Comcast and they say it should work. The only options for port forwarding on this modem are for TCP and UDP. We need the GRE packet forwarded to enable PPTP to reach the server. If we enable DMZ to the server, we can VPN to the server. However, this opens up all ports. We have called in and asked if they can enable PPTP passthrough on their end and they say they cannot. Is there a way to forward the GRE packet on this modem without using DMZ?
We have a Comcast Business SMC Networks modem hardware version 1B and are having problems getting PPTP to pass through. I have called Comcast and they say it should work. The only options for port forwarding on this modem are for TCP and UDP. We need the GRE packet forwarded to enable PPTP to reach the server. If we enable DMZ to the server, we can VPN to the server. However, this opens up all ports. We have called in and asked if they can enable PPTP passthrough on their end and they say they cannot. Is there a way to forward the GRE packet on this modem without using DMZ?
ASKER
yes, it is already forwarded.
Does the comcast unit have port triggering, too?
ASKER
yes
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This is an old post but Comcast has added the GRE protocol in the port forwarding tab of the firewall.
You have to create two rules:
You still have to have port 1723 forwarded to your server. Then you add the GRE protocol to forward to your server as well.
You have to create two rules:
You still have to have port 1723 forwarded to your server. Then you add the GRE protocol to forward to your server as well.
Another update...
The Internet Assigned Numbers Authority (IANA) has changed the link to their list of well-known/assigned ports...
here are the new URLs:
XML version - http://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xml
Text version - http://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.txt
The Internet Assigned Numbers Authority (IANA) has changed the link to their list of well-known/assigned ports...
here are the new URLs:
XML version - http://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xml
Text version - http://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.txt
Did you try forwarding port 1723 on both TCP and UDP?