Over the past few months Comcast has been updating the configurations on their business customers cable modems to roll out support for IPv6 addresses. IP addresses are unique identifiers used to send and receive information on the Internet and internal networks so users receive the information they requested. IP addresses are unique, like a postal address and zip code combination, allowing devices on different networks to communicate.
The current version of IP addressing is IPv4, an addressing scheme which has slowly run out of possible addresses to give because of the proliferation of devices on the Internet. As a result, IPv6 was developed to create additional addresses. Eventually IPv6 will be used by all devices but many devices are not configured to use it yet. If the servers and switches on an internal network are not configured for IPv6, having it enabled in the cable modem can cause connectivity issues on the network.
To check the cable modem (different for each model)
- Log into the cable modem
- Click on LAN Settings
- Scroll to verify the IPv6 settings are configured (this setting cannot be turned off)
- Log into a network device.
- Open "Control Panel" (If the options do not look like this, change the view to "Small Icons").
- Open "Network and Sharing Center".
- Click on "Change Adapter Settings".
- Right-click on the network adapter providing Internet access and select "Properties".
- Un-check the box next to "Internet Protocol Version 6 (TCP / IPv6)".
- Click "OK" to save the changes.