Common Problems from Xfinity’s IPv6 Changes

• Dynamic IPv6 Address Rotation Some users report their public IPv6 address changes daily, which disrupts secure logins, remote access, or services that rely on a stable IP.
• Modem/Router Compatibility Issues If your modem or router doesn’t fully support IPv6 or isn’t configured correctly, it may cause sporadic speed drops or failed connections. One user found their modem kept trying to lease an IPv6 address and failed, falling back to IPv4 intermittently.
• Partial Connectivity During neighborhood upgrades, some users temporarily lost IPv4 or IPv6, leading to slow speeds or inability to reach certain websites.
• Authentication or VPN Failures Services that depend on IP-based authentication may fail if your IPv6 address changes frequently.

🛠️ What You Can Do

• Check Your Equipment Ensure your modem and router support IPv6 natively. Devices like the Netgear CM1200 or CM2000 are known to work well with Xfinity’s setup.
• Router Configuration On routers like ASUS or TP-Link, look for IPv6 settings under WAN. You may need to choose “Native” or “Passthrough” depending on your setup. Avoid “Tunnel 6to4” unless you know what you’re doing.
• Disable IPv6 Temporarily If issues persist, disabling IPv6 on your router (if possible) may stabilize your connection. Some users report better performance sticking to IPv4 until Xfinity’s upgrades settle.
• Static IP Option If you need a consistent IP for remote access or server hosting, consider upgrading to a business-class plan with static IP options.