4 ms·

I've had the same IPv6 prefix (/60) from Comcast for over 2 years now. I set up my DHCPv6 client with a stable GUID and even after my equipment being off for a

I've had the same IPv6 prefix (/60) from Comcast for over 2 years now. I set up my DHCPv6 client with a stable GUID and even after my equipment being off for a couple of days I still pulled the exact same prefix delegation to my CPE. In my old house where I lived for ~9 years, I had the same IPv6 prefix (/60) from Comcast for a little over 5 years since I turned on IPv6 in 2015 and had not changed until I moved to SF. Sounds like there's something wrong with your CPE where it is not sending the same GUID to the DHCPv6 server and thus is getting a new prefix delegation each time.

ninkendo 4y ago
For the first few weeks using IPv6 I used a UniFi security gateway with some pretty standard config (you don’t get to adjust your DUID or anything) and a Comcast business gateway as my modem (it’s also a router, so if there’s a DUID misconfiguration it’s Comcast’s fault). So the Comcast gateway got a /56 and further delegated a /60 to my USG (the Comcast modem has no bridge mode, this is how it has to work), and my prefix still changed 3 or 4 times. I’ve since changed to my own modem and my own OpenBSD box with a statically configured DUID (randomly generated UUID persisted via the config file) in my dhcpcd.conf. My prefix still changed a few times. I’ve heard a lot of people saying their prefix has been mostly stable, but it hasn’t been the case for me. Maybe my account is misconfigured on Comcast’s end, maybe something else on their end is wrong, but I’ve checked everything and it looks right on my end. (My IPv4 address has remained perfectly stable this whole time too. Only my IPv6 prefix seems to be constantly changing. It’s the exactly the opposite of what I’d want, I could care less if my IPv4 address changes, I only need my IPv6 prefix to be stable.)

4 ms·

I've had the same IPv6 prefix (/60) from Comcast for over 2 years now. I set up my DHCPv6 client with a stable GUID and even after my equipment being off for a

by ArchOversight 4y ago

ninkendo 4y ago
For the first few weeks using IPv6 I used a UniFi security gateway with some pretty standard config (you don’t get to adjust your DUID or anything) and a Comcast business gateway as my modem (it’s also a router, so if there’s a DUID misconfiguration it’s Comcast’s fault). So the Comcast gateway got a /56 and further delegated a /60 to my USG (the Comcast modem has no bridge mode, this is how it has to work), and my prefix still changed 3 or 4 times. I’ve since changed to my own modem and my own OpenBSD box with a statically configured DUID (randomly generated UUID persisted via the config file) in my dhcpcd.conf. My prefix still changed a few times. I’ve heard a lot of people saying their prefix has been mostly stable, but it hasn’t been the case for me. Maybe my account is misconfigured on Comcast’s end, maybe something else on their end is wrong, but I’ve checked everything and it looks right on my end. (My IPv4 address has remained perfectly stable this whole time too. Only my IPv6 prefix seems to be constantly changing. It’s the exactly the opposite of what I’d want, I could care less if my IPv4 address changes, I only need my IPv6 prefix to be stable.)