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Re:IPv6 Excuse Bingo by ndriscoll on Tuesday January 23, 2024 @11:16AM (#39105334)
I just checked on xfinitywifi, and see that I get an ipv6 address there, so I assume Comcast has it turned on for customers that are using the ISP provided gateway at least. I don't know how common that setup is, but I'd guess the population that opts to buy their own equipment these days is more likely to be the type to mess around with their settings.
Re:IPv6 Excuse Bingo by oldandboring on Tuesday January 23, 2024 @12:06PM (#39106142)
I think you're right up to a point. For my office router I'm indeed using my own gateway in front of their modem which is acting as a bridge. But for my home network, it's the default gateway that came with my fiber service ~8 years ago that a ton of people still have.

My sense is this transition is going to take another 10+ years to get done. The big web properties where most people spend most of their time have the IPs to maintain IPv4 indefinitely, which will slow it way down. It's the smaller apps who are going to want to deploy IPv6-only who will generate consumer complaints: "I don't understand, why does Google work but this app doesn't? Why does it work from my phone when I'm out and about, or from work, but not from home?" The consumer won't exactly know who to direct these complaints to, the cause is non-obvious to most "tech support" people, and the fix is either too complex for consumers to implement or involves getting new equipment.

Re:IPv6 Excuse Bingo by bnabholz on Wednesday January 24, 2024 @11:32PM (#39126213)
I've had some gripes with Comcast/Xfinity in the past (as many have) but I feel like they are in the lead as far as residential IPv6 deployment (on by default), and I was originally using their own gateway, which as you mention just works with IPv6.

When I switched to my own modem and router (Arris and Ubiquiti/Unifi), I really wanted to dig in and understand IPv6 thoroughly. The modem acts as a bridge and the router gets a single /128 address, and then uses IPv6 Prefix Delegation (PD) over that link to request additional address space for clients (from a different subnet).

The Xfinity gateway only has one local network to support so it requests a single /64 PD, and then clients can use SLAAC (and optionally the privacy extensions) to acquire one or more addresses out of the /64.

When I switched to the Unifi equipment, through some trial and error I found out I could request up to a /60 from Xfinity. Some ISPs will do more, some will do less. No way to really tell, just request larger prefixes and see what you end up getting. Anyway, my /60 gave me 16x /64s to play with. It is wild that my address space is 68,719,476,736 times larger than the entire IPv4 address space.

I have a few VLANs, each of which gets assigned a /64 out of the /60, but even if I'm not using all 16 of them, Xfinity's routing table will send the entire /60 to me. So beyond my VLANs and directly-connected devices, I have the rest of the /60 to use for VMs, Kubernetes pods, etc. and I can add routes to direct that traffic to its next hop. It was a learning curve and a little unsettling that every VM or pod has a publicly routable address. But NAT != Firewall, so unsolicited inbound connections are still blocked, and not having to deal with NAT is very cool! Even though many networking people have it ingrained that private devices should have private addresses.