On Aug 9, 2011, at 11:47 AM, Joe Pruett wrote: > as i'm rolling v6 into my world, i'm not sure which way to go with > reverse dns conventions. for forward i'm doing things like: > > foo.example.com a 1.1.1.1 > foo.example.com aaaa 1000::1.1.1.1 > foo.v4.example.com a 1.1.1.1 > foo.v6.example.com aaaa 1000::1.1.1.1 > > so i can use a foo.v4/v6 hostname if i need to specify transit behavior. > > but for reverse i'm not sure if i want to map it like: > > 1.1.1.1.in-addr.arpa ptr foo.example.com. > 1.0.1.0.1.0.1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.1.ip6.arpa > ptr foo.example.com > > or: > > 1.1.1.1.in-addr.arpa ptr foo.v4.example.com. > 1.0.1.0.1.0.1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.1.ip6.arpa > ptr foo.v6.example.com > > being able to just use foo.example.com for authentication purposes > (sendmail, nfs, etc) is nice. but also knowing when incoming is v4 or > v6 by just looking at the dns lookup (for tools that do reverse lookup > for you) is also nice. > > what are you doing? which way makes more sense to you? >
My PTRs are all to the same host name. In any context where the protocol actually matters, you should have other ways to detect it. I also don't recommend doing the foo.v4/foo.v6 thing in your forwards. There's really no advantage to do it. Most tools either have separate IPv4/IPv6 variants or have command-line switches for address-family control if you care. Owen
