Double NAT Problem — How to Detect and Fix It

by Marcus Reed Updated Apr 24, 2026

Double NAT occurs when you have two routers performing NAT (Network Address Translation) on your network — typically when your ISP-provided gateway is followed by your own router. This can cause problems with online gaming, VPN connections, and port forwarding.

Figure 1 — Double NAT Problem — How to Detect and Fix It

Step-by-Step Guide

Detect double NAT — check your router's WAN IP. If it starts with 10.x, 172.16-31.x, or 192.168.x, you have double NAT.
Option 1: Bridge mode — set your ISP gateway to bridge mode to disable its NAT.
Option 2: Remove one router — if you don't need both, remove the extra router.
Option 3: DMZ — put your second router's IP in the first router's DMZ. Not ideal but works.
Option 4: Contact ISP — ask your ISP to put their gateway in bridge mode for you.

Related Guides

Video Tutorial

For more information, see Apple Support.

Pro Tip: Document your network settings before making changes. A screenshot of your router's config page can save hours of troubleshooting.

Key Takeaways

Restart your router first — this fixes 80% of issues
Test with Ethernet to determine if the problem is WiFi-specific
Check your DNS settings if websites won't load
Contact your ISP if all devices are affected — it may be their issue

Frequently Asked Questions

What is double NAT?

Double NAT happens when two devices on your network both perform NAT — usually an ISP modem/router combo plus your own router. Your traffic gets translated twice, causing issues.

Does double NAT affect gaming?

Yes. Double NAT can cause strict NAT types, making it difficult to join lobbies, use voice chat, or host games. Bridge mode is the best fix.

About Marcus Reed

Marcus Reed is a network technician and technical writer who has configured and troubleshot routers and modems across thousands of home and small business installations for major ISPs including Comcast, AT&T, and Spectrum. That field experience across different hardware, firmware versions, and ISP environments gives him a practical command of what goes wrong and why. At RouterHax, he covers brand-specific router setup guides, ISP modem compatibility, and step-by-step troubleshooting tutorials.