| > your external IPv4 address rarely changes Bad generalization. I'm sure policy about this differs a lot, but my consumer ISP definitely reassigns my home's v4 address periodically. I don't track it closely, but it seems that when my ONT power cycles more often than not it pulls a new v4 address. Now, basing my privacy/security on this would be bad, but to GP's point, if I was using a static v6 block, not only would this address never change, each device in my LAN would have an extra identifier attached to it. External hosts wouldn't merely be able to identify "my house", but traffic from "my phone", "my kid's switch", and "my spouse's phone" would all have distinct addresses. Of course, my ISP doesn't do v6 at all, so there's no dilemma :') |
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| ▲ | yjftsjthsd-h 19 hours ago | parent | next [-] | | That's also a poor generalization, though. Some ISPs rotate customer subnets, and devices can rotate their randomized IPs. | | |
| ▲ | spijdar 18 hours ago | parent [-] | | That's why I specified if one was using a static v6 network. There are several reasons why this might not be true, from ipv6 CGNAT like what cell providers do, to ISP rotation, to randomization in your own network, to NATing from the private network if you wanted. But it does seem like it would be far more likely de facto for an ISP to not randomly rotate v6 networks, except maybe to discourage hosting on consumer connections? |
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| ▲ | RulerOf 17 hours ago | parent | prev | next [-] | | > using a static v6 block, not only would this address never change, each device in my LAN would have an extra identifier attached to it. This is not true. IPv6 stack allocates at least 3 addresses: - Link-local
- "Permanent" Address derived from the subnet and MAC
- Temporary address that changes several times per day The default address for new connections is always the temporary address. So IP-based tracking from outside your network will be no better than it was before from one day to the next—the /64 will be the only constant here, just as your router's WAN IPv4 is for v4 connections. | | |
| ▲ | spijdar 15 hours ago | parent [-] | | Ah, handy! Though it can't always be true, at least for manual configuration ;-) I have two VPSes with v6 addresses (the others don't have it configured...), and both only have LL and their permanent Internet addresses. My understanding is v6 has two different autoconf schemes, DHCPv6 and a more "native" solution. Do these both always result in interfaces having multiple (routable) addresses? Most of my IPv6 experience has been setting it up on aforementioned VPS, and being rewarded with slow OS updates, since NetBSD's default CDN, Fastly, blackholes PMTUD, so I had to drop the MTU on the interface just to get v6 TCP connections to work at all[0]. And for point-to-point networking in an overlay VPN, where I just discovered that Chromium has an 11-year outstanding "bug" where it refuses to perform AAAA lookups if you don't have public IPv6 routing. [0] I could switch mirrors, but the bandwidth drop isn't quite bad enough for me to bother... |
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| ▲ | icedchai 9 hours ago | parent | prev [-] | | If you had v6, they'd probably also reassign your IPv6 prefix delegation, too. Also, v6 supports "privacy extensions", essentially randomizing the host portion of the address and periodically rotating it, so it is not accurate to say your address would never change. |
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