S

Visitor

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4 Messages

Sunday, July 24th, 2022 1:22 PM

Closed

Port Forwarding on 443 doesn't work from LAN network

I have set up port forwarding for port 443 from Xfinity Gateway to my home server. It works fine if the connecting device is not in the home network, but it fails to connect if the device is in my home Xfinity network. I have reached out to Xfinity technical support for this. They have a hard time understanding my issue.  

Can anyone help to resolve this issue?

Problem Solver

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1.1K Messages

3 years ago

Hello there, @ss07. I am sorry to hear you are having issues with this port. Is this the only port that this issue occurs on? 

Visitor

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4 Messages

@XfinityKorie​ Yes. I don't have any issue with other ports. 

Note: The port forwarding for port 443 works perfectly from outside of the home network (from WAN). The issue is only from my internal LAN network (IP: 10.0.0.x)

(edited)

Problem Solver

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1.1K Messages

I'd like to look into this for you! Can you send us a peer to peer message with your name and address? 

 

To send a "Peer to peer" message:

Click "Sign In" if necessary

• Click the "Peer to peer chat" icon

• Click the "New message" (pencil and paper) icon

• Type "Xfinity Support" in the "To:" line and select "Xfinity Support" from the drop-down list which appears. The "Xfinity Support" graphic replaces the "To:" line

• Type your message in the text area near the bottom of the window

• Press Enter to send it

I no longer work for Comcast.

Problem Solver

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1.1K Messages

3 years ago

Have you used this port in the past, and it just started having issues, or first time using it? When trying to connect via LAN, do you get any error code or messages? 

Visitor

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4 Messages

@XfinityKorie​ I am a new customer. This was working fine before I moved to Xfinity. I get connection time out when I try it from my Xfinity Gateway Wifi network. If I switch it to a Cellular connection, it works. 

Visitor

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4 Messages

3 years ago

I have same issue but with a connection that previously worked.  Was this issue resolved?

Problem Solver

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339 Messages

Good morning, @user_909945

 

I would be happy to help with your port forwarding issues as well.

 

Could you please send our team a direct message with your full name and full address? Our team can most definitely take a further look at this issue. To send a "Peer to peer" ("Private") message:

Click "Sign In" if necessary

  • Click the "Peer to peer chat" icon
  • Click the "New message" (pencil and paper) icon
  • Type "Xfinity Support" in the "To:" line and select "Xfinity Support" from the drop-down list which appears. The "Xfinity Support" graphic replaces the "To:" line
  • Type your message in the text area near the bottom of the window
  • Press Enter to send it

I no longer work for Comcast.

Visitor

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4 Messages

3 years ago

Is there any resolution for this issue? Otherwise, I have to move out of Xfinity. 

Visitor

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4 Messages

3 years ago

I fought with this issue for days and was unable to get a resolution.  I finally purchase a 3rd party modem/router to replace the xfinity unit and was then able to set-up multiple ports for forwarding.

Problem Solver

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1.5K Messages

3 years ago

Port forwarding doesn't resolve names.  That just blows a hole in your firewall so inbound traffic on your external IP address, and a specific port, ends up on a box you specify.

You can get to the box by opening up a web browser and typing https://INTERNAL IP-ADDRESS:443 though right? 

Gateways don't run DNS servers themselves.  Some gateways can act as a DNS proxy though.  I don't know if Xfinity's can or not, I think they may have removed that when they fixed your DNS servers to 75.75.75.75/76.76.76.76.  The internal DHCP server only passes out these addresses to your internal clients and may have no other function.  With other gear, you can pass out your gateway internal address (10.0.0.1) for a DNS server to DHCP clients, and if DNS proxy works on it, and then it will resolve internal hostnames while using upstream DNS servers as backups.  Not all do this.

You can also resolve your internal network machines by setting up your own internal DNS server, and manually specifying that in a client network configuration.  Other gear such as a firewall can run a "resolver" that will automatically map hostnames that connect to the internal DHCP server and append a domain name you specify.  You can also setup a "hosts" file on a client machine that points to a box on your internal network, but the can be problematic when connecting to other networks.  

You can test the behavior.  Get a command prompt and type "nslookup".  Then change the server you are using.  Point it at your gateway with the "server 10.0.0.1" command.  Then enter a hostname on your internal network.  If you get nothing, it doesn't have the feature.

Expert

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110.1K Messages

@ss07  @flatlander3​ wrote;

Some gateways can act as a DNS proxy though.  I don't know if Xfinity's can or not, I think they may have removed that when they fixed your DNS servers to 75.75.75.75/76.76.76.76. 

FWIW. The Comcast rented gateway devices no longer act as DNS forwarders / DNS relays. You're locked in to using their DNS servers.

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