There is a confirmed firmware bug with SB6183 (and other modems using the same Broadcom chipset), that causes severe packet loss for IPv6 TCP6 packets with timestamp option set. Since this is the default behavior for some OS's TCP stacks (e.g. modern Linux kernels, some Andriod builds, etc), it makes IPv6 almost unusable on those systems.
This fix has been verified by Comcast, and customers affected by the problem in Oct, 2015, when Arris provided the new firmware.
I'm trying to find out if any engineers or techs from Cox have this on the radar, and know if/when they expect to get a new firmware with the fix for this issue. It has been plaguing me since upgrading my modem.
There is a good write-up about this problem, by Dan found here:
http://blog.dan.drown.org/sb6183-dropping-ipv6-traffic/
This is the long Comcast thread, that ran its course to resolution.
https://www.dslreports.com/forum/r29569626-IPv6-SB6183-IPv6-problems
Sincerely,
Ben
↧