How to Port Forward Modem Router for AT&T

This guide is about port forwarding your modem router for AT&T. The process will enable you to enter ports for a better internet experience. Port forwarding makes you enjoy games, applications, and file sharing. 

We will simply explain the process. After reading this guide, you will be able to access servers behind the firewall or router, NAT, or CGNAT.

Understanding Port Forwarding and Why It Matters

Port forwarding directs incoming internet traffic to a specific device on your local network by opening designated ports. This is essential for:

• Online gaming (reducing lag and improving connectivity)
• Remote desktop access (controlling a PC from afar)
• Hosting web/FTP servers (running personal websites or file-sharing services)
• Security cameras & smart home devices (accessing feeds remotely)

However, AT&T’s gateways sometimes use Carrier-Grade NAT (CGNAT), which can block incoming connections. We’ll explore workarounds for this later.

Requirements for modem router

• The IP address of your router.
• The IP address of your device.
• TCP and UDP port numbers. 
• Remote IP address.
• Your gateway information (model number and series)

Step-by-Step Guide to Port Forwarding on AT&T Modems

1. Identify Your AT&T Gateway Model

AT&T provides various modem/router combos, including:

• BGW210, BGW320 (common for fiber users)
• Pace 5268, NVG589, 2Wire 3801 (legacy models)
• Motorola 2210, Netgear 6200 (for DSL users)

Check the label on your device to confirm the model.

2. Access the Gateway’s Admin Panel

1. Open a browser and enter:
   • http://192.168.1.1 (most models)
   • http://homeportal (some older gateways)
2. Log in using the default credentials (found on the gateway label).

3. Configure Port Forwarding Rules

Steps vary slightly by model, but the general process is:

For BGW210/BGW320:

• Go to Firewall > NAT/Gaming
• Select Custom Services
• Enter:
  • Global Port Range: The external port (e.g., 55000)
  • Base Host Port: The device’s internal port (same as above)
  • Protocol: TCP, UDP, or both
  • Internal IP: The local device’s IP (e.g., 192.168.1.100)

For Older Models (2Wire 3801, NVG589):

• Navigate to Settings > Firewall > Applications, Pinholes, and DMZ
• Select your device or manually enter its IP
• Add a new user-defined application:
  • Name (e.g., “Minecraft Server”)
  • Protocol (TCP/UDP)
  • Port range (same in “From” and “To”) 12

4. Save and Test the Configuration

Verify port openness using tools like PortCheckTool.com.

Restart your gateway and device.

AT&T ports needed to run

Some of the default ports are: 

Internet browsing: Ports 80 (HTTP) and 443 (HTTPS) are commonly used for web browsing.

Email: Ports 25 (SMTP), 110 (POP3), and 143 (IMAP) are commonly used for email.

Voice over IP (VoIP): AT&T uses various ports for VoIP, including 5060 (SIP), 5061 (SIP-TLS), and a range of ports for RTP (audio) and RTCP (control).

IPTV: AT&T’s U-verse IPTV service uses a range of ports for video streaming, including 5001 (UDP) for the video data, and 64444 (TCP) for the control data.

Gaming: The specific ports needed for online gaming will depend on the game and platform being used. However, common ports used for gaming include 3074 (UDP) for Xbox Live, 80 (TCP), and 443 (TCP) for PlayStation Network.

You can also consult your modem’s documentation or contact AT&T customer support for more information on the specific ports and protocols needed for your setup.

Common Issues & Troubleshooting

1. Double NAT Problems

If you’re using a secondary router (e.g., ASUS, Eero), AT&T’s gateway may conflict, causing double NAT. Solutions:

• Enable IP Passthrough (BGW320/BGW210):
  • Set Allocation Mode = Passthrough
  • Enter your router’s MAC address
  • Disable AT&T’s Wi-Fi to avoid interference
• Bridge Mode: Some ISPs allow this, but AT&T often requires their gateway to stay active.

2. CGNAT Blocking Ports

If your WAN IP starts with 100.x.x.x, AT&T is using CGNAT. Workarounds:

• Request a Public IP (contact AT&T support).
• Use a VPN with Port Forwarding (e.g., PureVPN’s add-on).

3. Firewall Conflicts

• Disable Packet Filtering in AT&T’s firewall settings.
• Ensure your device’s local firewall (Windows/Mac) isn’t blocking the port.

Unblock ports safely with PureVPN 

With the PureVPN port forwarding add-on, opening ports has become easy and efficient. You can enjoy port forwarding features to unblock all ports you wish to.

How to Access Ports Behind CGNAT

Accessing ports is a hassle. ISPs perform CGNAT to restrict the use of IPv4 addresses. This increases your latency, resulting in slow internet speed. Your firewall is also configured by default to restrict ports. CGNAT and firewall restrictions can be bypassed using the PureVPN port forwarding add-on. Here’s how:

Here is how you can use PureVPN to port forward AT&T router in just a few clicks:

1. Sign up for PureVPN, add Port Forwarding to your plan, and complete the payment. 
2. Download and install the PureVPN app, launch it, and log in using your credentials. 
3. Access the PureVPN Member Area, go to Subscriptions and click Configure next to Port Forwarding. 
4. Choose Enable specific ports, enter the ports you want to open, and click the Apply Settings button. 
5. Open the PureVPN app, connect to a port forwarding-supported server, and you are good to go!

PureVPN’s port forwarding add-on: A secure solution for unblocking ports

Every modem or router has different procedures to allow port forwarding. Sometimes, you need to have forwarded ports, while you are playing multi-server games, sharing files and documents, or wishing to access live web cameras.

If you are a subscriber of AT&T, you get certain ports open through contacting them, but not all. Also, if you surpass the CGNAT, your IP might be blocked. All these problems are catered under the roof of PureVPN’s port forwarding add-on, your friend in need. Just a click will get you through the barriers.

Conclusion

Port forwarding on AT&T gateways isn’t just for gamers—it’s a gateway to enabling remote access, secure home automation, and productive remote work. While each router model has its quirks, the core steps remain consistent: identify, log in, configure, assign, and test. Always follow security best practices to keep your network fortified.

If you hit snags, double-check the rule is enabled for the correct device (a frequent oversight), ensure local firewalls aren’t blocking traffic, and verify you’re not stuck behind CGNAT—or use AT&T’s Port Forwarding Tool in that case.

Frequently Asked Questions