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My work network has a /64 for WAN (yes quite a lot of addresses for a point to point link) and a /48 for "internal use". So WAN is merely a few billion IPs and

My work network has a /64 for WAN (yes quite a lot of addresses for a point to point link) and a /48 for "internal use". So WAN is merely a few billion IPs and VLANS - gazillions of IPs. OK we also have six other WANs and allocations but that is another story. We have no need for NAT in the traditional IPv4 sense but NPT is handy for failover and that is why it was invented because IPV6's design lacked one crucial thing: telling the clients which internets are available so they can select which local address to start out from. Perhaps everyone should run BFD(v6) by default.

throw0101a 4y ago
> My work network has a /64 for WAN (yes quite a lot of addresses for a point to point link) […] Technical footnote: /127 addresses are supported (and were a thing for a short while) on inter-router links: * https://datatracker.ietf.org/doc/html/rfc6164 https://datatracker.ietf.org/doc/html/rfc6164 Technical technical footnote: you can just use link-local address for inter-router links because all the router cares about is the next next-hop, and you don't need a globally routable address for that. In an IPv6 network, it is possible to use only link-local addresses on infrastructure links between routers. This document discusses the advantages and disadvantages of this approach to facilitate the decision process for a given network. * https://datatracker.ietf.org/doc/html/rfc7404 https://datatracker.ietf.org/doc/html/rfc7404
- gerdesj 4y ago
  "Technical footnote: /127 addresses are supported" Yes they are but I want a shit load of stuff on my WAN available to the world and I don't want to piss around with NAT n that. The IPv6 address-space is big enough to deal with PtP links. It doesn't really matter, You could do a /127 for WAN and then I allocate a /64 from my /48 for WAN. Or you could use a recent RFC that enables a /64 or smaller to be used for WAN without a separate allocation.

throw0101a 4y ago

> My work network has a /64 for WAN (yes quite a lot of addresses for a point to point link) […] Technical footnote: /127 addresses are supported (and were a thing for a short while) on inter-router links: * https://datatracker.ietf.org/doc/html/rfc6164 https://datatracker.ietf.org/doc/html/rfc6164 Technical technical footnote: you can just use link-local address for inter-router links because all the router cares about is the next next-hop, and you don't need a globally routable address for that. In an IPv6 network, it is possible to use only link-local addresses on infrastructure links between routers. This document discusses the advantages and disadvantages of this approach to facilitate the decision process for a given network. * https://datatracker.ietf.org/doc/html/rfc7404 https://datatracker.ietf.org/doc/html/rfc7404

gerdesj 4y ago
"Technical footnote: /127 addresses are supported" Yes they are but I want a shit load of stuff on my WAN available to the world and I don't want to piss around with NAT n that. The IPv6 address-space is big enough to deal with PtP links. It doesn't really matter, You could do a /127 for WAN and then I allocate a /64 from my /48 for WAN. Or you could use a recent RFC that enables a /64 or smaller to be used for WAN without a separate allocation.