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NAT is actually useful besides just avoiding address exhaustion. Many IPv6 networks are on NAT anyway, like pretty much every cell carrier, which maybe accounts

NAT is actually useful besides just avoiding address exhaustion. Many IPv6 networks are on NAT anyway, like pretty much every cell carrier, which maybe accounts for most ipv6 traffic.

toast0 1y ago
> like pretty much every cell carrier TMo US gives me a whole routed /64. Why build and staff v6 NAT devices for no reason? At least several years ago several cell carriers were all about v6 to reduce the volume of v4 traffic they carry, because v4 requires expensive addresses, expensive nat boxes, and expensive people to feed and care for the NAT boxes.
- morshu9001 1y ago
  Honestly, I don't know why so many carriers do v6 with NAT, cause intuitively they wouldn't. Maybe someone else knows. I know why a home or office would do it, it's easier to reason about there.
  - Symbiote 1y ago
    Can you give an example of an ISP doing IPv6 NAT?
    - morshu9001 1y ago
      AT&T
      - Symbiote 1y ago
        I can't see anything in their documentation about that, or anything on forums/Reddit. Users ask about prefix delegation and advanced configurations, but all start from being allocated a /64.
        morshu9001 1y ago
        I got a private IPv6 only on AT&T cell when I checked a couple of years ago (to be clear, not a public one with inbound-deny). Will check again. Edit: Ok not sure what to make of this now. On an iPhone rn so it's tricky, the Net Analyzer app says I have 5 2600:s on cell, which should be the public range, but my public IP according to test-ipv6.com is a different 2600: from all the above. Wonder if those 5 are actually the EPC. There's an HN comment about them using NAT: https://news.ycombinator.com/item?id=23025344 https://news.ycombinator.com/item?id=23025344 and this forum thread https://wirelessjoint.com/viewtopic.php?p=25357 https://wirelessjoint.com/viewtopic.php?p=25357 There's an old Reddit thread where someone said at first there's no NAT, but then realized there is https://www.reddit.com/r/ATT/comments/8k680y/cellular_public_ipv6_address/ https://www.reddit.com/r/ATT/comments/8k680y/cellular_public...

NAT is actually useful besides just avoiding address exhaustion. Many IPv6 networks are on NAT anyway, like pretty much every cell carrier, which maybe accounts for most ipv6 traffic.

toast0 1y ago

> like pretty much every cell carrier TMo US gives me a whole routed /64. Why build and staff v6 NAT devices for no reason? At least several years ago several cell carriers were all about v6 to reduce the volume of v4 traffic they carry, because v4 requires expensive addresses, expensive nat boxes, and expensive people to feed and care for the NAT boxes.

morshu9001 1y ago
Honestly, I don't know why so many carriers do v6 with NAT, cause intuitively they wouldn't. Maybe someone else knows. I know why a home or office would do it, it's easier to reason about there.
- Symbiote 1y ago
  Can you give an example of an ISP doing IPv6 NAT?
  - morshu9001 1y ago
    AT&T
    - Symbiote 1y ago
      I can't see anything in their documentation about that, or anything on forums/Reddit. Users ask about prefix delegation and advanced configurations, but all start from being allocated a /64.
      - morshu9001 1y ago
        I got a private IPv6 only on AT&T cell when I checked a couple of years ago (to be clear, not a public one with inbound-deny). Will check again. Edit: Ok not sure what to make of this now. On an iPhone rn so it's tricky, the Net Analyzer app says I have 5 2600:s on cell, which should be the public range, but my public IP according to test-ipv6.com is a different 2600: from all the above. Wonder if those 5 are actually the EPC. There's an HN comment about them using NAT: https://news.ycombinator.com/item?id=23025344 https://news.ycombinator.com/item?id=23025344 and this forum thread https://wirelessjoint.com/viewtopic.php?p=25357 https://wirelessjoint.com/viewtopic.php?p=25357 There's an old Reddit thread where someone said at first there's no NAT, but then realized there is https://www.reddit.com/r/ATT/comments/8k680y/cellular_public_ipv6_address/ https://www.reddit.com/r/ATT/comments/8k680y/cellular_public...