A free open port check tool used to detect open ports on your connection. Test if port forwarding is correctly setup or if your port is being blocked by your firewall or ISP.
6 Messages
Unable to connect to web server inside my network with port forwarding from an outside network.
Date: 11/08/2024
I'm trying to setup port forwarding to an Apache webserver on port 80. I'm unsure if the port forwarding from the internet is being blocked by the ISP (Xfinity). Has anyone been able to get port forwarding to work on Xfinity recently (in 2024)?
Diagram:
Computer on Internet --> Xfinity --> Cable modem (Arris SurfBoard Model: S33) --> Router MT6000/Flint2 (Firmware v4.6.8)--> Computer on my network hosting an Apache webserver on port 80.
Settings:
Xfinity settings:
Unknown - There currently does not seem to be a way to setup port forwarding if you do not have one Xfinity's cable modems/routers (Gateways). This should be done in one's router. To avoid problems in the Xfinity app the two-step verification has been disabled. Xfinity tech support has been unhelpful thus far.
Xfinity port forward directions:
https://www.xfinity.com/support/articles/port-forwarding-xfinity-wireless-gateway
xFi Users (xFi Gateway) Using Xfinity app <-- suggested to click WiFi in app and go to "Advanced Settings". The only options are Troubleshoot and WiFi Hotspots if you are not using their equipment.
Non-xFi Xfinity Gateway User (Xfinity Gateway): <-- suggest to use Admin Tool if you have an Xfinity Gateway. The URL http://10.0.0.1/ times out if you do not. To find your gateway IP in Windows go to the CMD prompt and type ipconfig /all and find your Default Gateway IP and enter that into your browser instead.
Note: According to Xifinity documents port 80 is not a blocked port:
https://www.xfinity.com/support/articles/list-of-blocked-ports
Note: Using the Xfinity app it seems you can no longer access port forwarding using the Assistant. This was done in the past by clicking on Account/Xfinity Assistant/ Xfi / Network / Open advanced settings / Port forwarding / This now displays the error message "Sorry, we're having some trouble gathering the list of your port forwards. If the problem persists, check back later."
Arris SurfBoard Model: S33 (Cable Modem) Settings:
There are no port forwarding settings since this is strictly a cable modem. Straight cable Modems are simply "pass through devices". You do not need to place it into "bridge mode" like you would if it were an Xfinity Gateway (combo modem/router).
MT6000/Flint2 Settings:
To setup port forwarding with this router. The port forwarding setting are found in two places. The 2nd location allows the ports to be publicly reached.
1st Found under: Network/Port Forwarding
2nd Found under: System/Security/Open Port on Router
https://docs.gl-inet.com/router/en/4/interface_guide/security/
Testing:
Windows Defender is turned off for testing.
Xifinity ISP in my area doesn't look like it is using CGNAT (Carrier Grade NAT). Link on how to check on Windows 10/11:
Internet search for "What is my IP address" allows me to find what my public IP address is. This is the address you type in to access your router from outside your home network.
When connected to my home network (LAN) I can enter either the public IP address or the direct IP address of my webserver and the Apache webserver page is shown.
When attempting to access my home network via the public IP address from an outside computer a time out message in the web browser is received. If I changed the port number to something other than 80 under the MT6000/Flint2 router's Port Forwarding settings, I am able to access the Admin login page for the router. However, no port forwarding occurs.
Used CanYouSeeMe
Open Port Check Tool -- Verify Port Forwarding on Your Router
Received:
Error: I could not see your service on 73.192.XXX.XX on port (80)
Reason: Connection timed out
user_46bvj0
6 Messages
13 days ago
This is interesting even though Xifinity/Comcast docs claim that port 80 is not being blocked...
I just asked the question to the Xfinity Assistant and got a message back stating that port 80 IS being blocked "... to protect users from potential security and privacy vulnerabilities."!
(edited)
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BruceW
Gold Problem Solver
•
26K Messages
12 days ago
The Assistant tells me, in response to "Is port 80 blocked?":
Please be aware that there are 2 kinds of responses in this Forum: Replies and Comments. When you Comment on a post by scrolling down to "Comment on this post here...", I am notified of your response. But if you select Reply, I am NOT notified and may not be aware of your response.
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XfinityTony
Official Employee
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1K Messages
12 days ago
@user_46bvj0 Good evening! Thank you for your detailed post. It's always super helpful. Regarding Port 80, I can only find documentation stating that it is not one of our blocked ports. The Xfinity Assistant saying it is a blocked port is interesting. I will be taking that back to figure out why we have two different answers out there.
I would definitely reach out to your router manufacturer about getting port forwarding to work. We don't have any articles on how to do that on third party routers because we that is outside our realm. That is up to the manufacturers to implement and you to configure. We can only help you set it up with Xfinity Gateways. Let me know if you have any other questions.
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BruceW
Gold Problem Solver
•
26K Messages
10 days ago
That's incorrect. In fact, Comcast/Xfinity DOES use CG NAT. See, for example,
https://forums.xfinity.com/conversations/your-home-network/packet-loss-on-xfinity-network-in-atlanta/65395fe377679f48f5bbfc95?commentId=6539c353e05b5f65da045833&replyId=653a6680e05b5f65da047739.
The first Comcast/Xfinity hop in the trace in that thread is in the CG NAT range. A more readable version of the trace image is at:
https://prod-care-community-cdn.sprinklr.com/community/cd58a8fd-ee2e-46c9-8c79-e9309441066e/dns.google_10252023_03-5f8b28ce-b3de-446b-8b80-8f19a9dc6a23-2086096517.png.
Also see
https://en.wikipedia.org/wiki/Carrier-grade_NAT.
Please be aware that there are 2 kinds of responses in this Forum: Replies and Comments. When you Comment on a post by scrolling down to "Comment on this post here...", I am notified of your response. But if you select Reply, I am NOT notified and may not be aware of your response.
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