Port forwarding shows as added in Xfinity app, but it’s not working — IP reservation/DHCP issues?

Troubleshooting Port Forwarding Failures in Xfinity Networks: Static IP and DHCP Challenges

Setting up port forwarding is a common requirement for gamers and remote access users alike, especially when hosting servers such as Minecraft Bedrock editions. However, users often encounter perplexing issues where the Xfinity mobile app indicates that port forwarding has been successfully configured, yet the intended ports remain closed. This article explores a typical scenario involving IP reservation and DHCP conflicts, offers insights into possible causes, and provides practical solutions to ensure port forwarding functions as intended.

Understanding the Issue

In many cases, users attempt to establish port forwarding rules through the Xfinity mobile app, expecting their server or device to be accessible externally. A typical sequence might involve:

Configuring port forwarding rules via the app, which reports success.
Verifying that the device has a static or reserved IP address within the local network.
Finding that despite reservation attempts, devices continue to use DHCP-assigned IPs, leading to inconsistent configurations.
Attempting to manually assign IP addresses through the router’s web interface, only to find changes do not persist.
Noticing conflicts where the IP address requested is reported as already in use, though the device remains accessible via its original IP.

This scenario suggests underlying issues with IP reservation, DHCP handling, or router firmware behavior, which can interfere with port forwarding rules.

Possible Causes and Contributing Factors

DHCP and IP Reservation Conflicts: The router may report an IP reservation as successful, but the device still receives a dynamic IP from DHCP, causing discrepancies.
Web Interface vs. Mobile App Discrepancies: Changes made through different interfaces may conflict or not synchronize properly, leading to inconsistent configurations.
IP Address Conflicts: Multiple devices or manual attempts to assign static IPs can cause conflicts, especially if reservation entries are duplicated or not properly applied.
Router Firmware or Software Bugs: Firmware bugs can cause reservation changes or port forwarding rules to not stick, necessitating firmware updates or resets.