Port forwarding, or port mapping as it is sometimes referred to, is a routing feature that allows users to access devices on the Internet that are behind a firewall. Ports may also require mapping to allow applications on the Internet to function properly. Configuration requires multiple steps and may fail to succeed due to certain variables. See below for just a few common issues, then head over to our Support Portal for a full checklist of troubleshooting suggestions.
- Can you reach the WAN IP address from a remote connection?
- Often, this means the destination device has a publicly-routable WAN IP. Note that the connection may be NAT’d and the address seen from the Web (e.g.: whatismyip.com) may not be the address on the WAN interface of the router. This is especially common for cellular connections.
- These specific IP address ranges (RFC 1918) are reserved specifically as non-routable addresses to be used in private networks:
- 10.0.0.0 through 10.255.255.255
- 172.16.0.0 through 172.32.255.255
- 192.168.0.0 through 192.168.255.255
- If the router receives a WAN IP address within any of these private ranges, this means that connections originating from the Internet will not be able to get past the NAT router (without port forwarding) in order to actually reach the router’s WAN interface.
- Cellular carriers may use addresses in the RFC 6598 space.
- The RFC 6598 address space includes addresses from 100.64.0.0/10 to 100.127.255.255
- These specific IP address ranges (RFC 1918) are reserved specifically as non-routable addresses to be used in private networks:
- Often, this means the destination device has a publicly-routable WAN IP. Note that the connection may be NAT’d and the address seen from the Web (e.g.: whatismyip.com) may not be the address on the WAN interface of the router. This is especially common for cellular connections.
- Rule configured incorrectly
- Check that you have the correct port(s) as well as protocol (TCP, UDP) and the Server’s LAN IP address (i.e. the device you are forwarding ports for).
- Don’t have all the needed ports configured
- Sometimes multiple forwarding rules are needed for the same address. Check with the manufacturer of the server device to confirm this if needed
- Is a single port needed or should you use a Port Range?
- Server is not responding locally
- Try to communicate with the Server device locally first. If this does not work, remote access will not either.
- Port conflict
- There is already a rule that exists or another device on the LAN using the port(s) in question.
- IP conflict
- The IP address used by the Server device also belongs to another device on the LAN.
