Netgear Working On IPv6 Modem Update For Comcast

Netgear said it will provide Comcast a firmware update for one of its DOCSIS 3.0 cable modems to make the devices compatible with IPv6, after several hundred of the MSO's customers lost Internet connectivity last week when Comcast put the next-generation protocol into operation in several markets.

"Recently, some Comcast customers lost their Internet connection due to an IPv6-compatibility issue we have with the Netgear CMD31T high-speed cable modem," Netgear said in a statement Thursday. "We are providing a firmware upgrade to Comcast for certification to make these devices IPv6 capable."

Comcast on Wednesday said it was rolling back its IPv6 deployment in some markets because of the glitch in the Netgear cable modems. The issue affected fewer than 1,000 subscribers, according to a source close to Comcast.

Once Comcast has certified the upgrade, the MSO will push it out across their network.

"Resolving this issue for customers in a timely fashion is our number one priority and we are working closely with Comcast on the solution," Netgear said. "We apologize for any inconvenience we have caused our customers."

According to Comcast, the Netgear CMD31T device currently "runs an uncertified version of firmware that exacerbates a critical IPv6-related defect," which prevents the device from being provisioned on the Comcast network. The cable operator is in the process of deploying IPv6 nationally, in a "dual-stack" implementation in which both IPv6 and IPv4 are supported on the client.

Comcast provides an "IPv6-readiness" check at for any Internet user to check for IPv6 compatibility problems.