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New Member

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3 Messages

Fri, Nov 12, 2021 11:57 PM

Remote Desktop connection through modem to firewall

This used to work. We use Remote Desktop Connection to connect to our public IP address including a port number (50.n.n.33:51115) to a specific computers port 3389. The port forwarding rules are on our firewall device. We can’t get the Comcast modem to pass the 51115 port number thru to the firewall.

With the modem in non-bridge mode, its WAN IP is not our assigned static IP. Using the WAN iP with RDC fails with the target computer not being found. Incidentally pinging the static IP is not found. Pinging the WAN IP works.

As a test, I plugged a computer into the modem LAN port and using the firewalls WAN IP was able to remote into the target PC, so the forwarding rules on the firewall are working.

this morning I had bridge mode enabled on the modem. Trying to RDC to our static IP still doesn’t work. RDC to the IP the modem reports as the WAN IP doesn’t work. RDC to the firewalls WAN IP, which now seems to be coming from Comcast, doesn’t work. The firewall WAN IP is set to be set by DHCP.

Help! Any suggestions?

Do I need to set the firewall WAN IP to the static IP assigned to us by Comcast? Our firewall is using pfSense.

Official Employee

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27 Messages

2 m ago

Hi there! We would be happy to assist you. Can you initiate a chat and start with your full name and address? To start a chat, please click the chat icon in the top right of the page next to the bell, and send your message to "Xfinity Support". Talk to you there! 

New Member

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3 Messages

Hi, I'm not going to be able to chat until probably Wednesday. Until then, please let me provide a few more details.

We have a static IP of 50.199.13.49, with CIDR block number 50.199.13.48/30, gateway IP address 50.199.13.50, and subnet mask of 255.255.255.252. Our comcast modem has been set to bridge mode. Logging on to the comcast modem web page, it lists the WAN as 24.19.238.26 with gateway 24.19.238.1. It's LAN IP is 10.1.10.1.

Question #1: Why is the WAN IP different from our assigned static IP?

We have a Netgate device running pfSense firewall. Right now it is using DHCP and is showing the WAN address of 73.140.128.51. Where is this coming from?

Question #2: We are trying to use Remote Desktop Connection to connect to a church computer using the address 50.199.13.49:51115. The firewall is forwarding incoming port 51115 to a specific internal computer's port 3389. At this moment, I can use RDC to connect to 73.140.128.51:51115 and it successfully remotes into the target internal computer. (Port 51115 is not the actual port number we're using.)

To get our assigned static IP working, do I need to go the the pfSense firewall and give its WAN port the static IP of 50.199.13.49? I don't know if you are familiar with pfSense, but to give its WAN a static IP and CIDR value. Would the correct value be 50.199.13.49/30? It also asks for the IPv4 Upstream gateway. Do you know what this should be?

If you could please answer these questions, I think I'll be good to go.

Brian

Official Employee

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12 Messages

I can't say from my end yet why this set-up is giving you some trouble. I don't have a guide as far as setting up pfSense with our network. I can certainly dig into the details when you are ready, and we help open up the path to getting some answers. 

New Member

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3 Messages

Thank you for your assist. I'll take it from here with the pfSense support folks.