Note: If available, we highly recommend consulting an IT or networking professional when dealing with network issues.
- Confirm that all ports and cabling are functional:
- Plug the affected phone in to a different Ethernet port.
- Switch out the Ethernet cable of the affected phone for a different one.
- Unplug the affected phone, and try a working phone with the same port/cable.
- See if you can access phone's web interface (GUI) by typing phone's IP address into a web browser. An inablity to access the web GUI is a solid indicator that there is a network problem (such as the phone being on the wrong subnet, which can be confirmed by running ipconfig to compare the phone's IP with a computer's on the same network.)
- Check firewall settings.
- If possible, ensure the phones are passing through only one router (a modem/router combo gateway connected to an additional standalone modem is a potentially problematic setup).
- Disable SPI and SIP-ALG in the router (if able) and reboot the router.
- Set both primary and secondary DNS on the routers to point to a public DNS such as 220.127.116.11 or 18.104.22.168, then perform a network power cycle.
The IT or network administrator should contact 8x8 Technical Support. Identifying account information (such as the Passphrase) will be required.