When double NAT is causing your issues

Double NAT happens when there are two routers in your network (e.g., your ISP's modem-router plus your own router).

How to fix it

1. Confirm with your router admin page — it usually warns about double NAT.
2. Put one of the routers in bridge mode (usually the ISP's).
3. If bridge mode isn't available, forward ports on both devices in sequence.

Tip: Ask your ISP for a "modem-only" mode — many offer it for free.