John, > John C Klensin wrote: > My goal is precisely to avoid ending up with either two > standards or eight verbs. Explanation of the latter: > > IPv4 IPv6 & self-referent DNS StableID > address address > RFC 959 2428 ??? ??? > Verb PORT,PASV EPRT,EPSV ?DPRT,DPSV? ?IPRT,IPSV? > > That seems to me excessive, if we can avoid it. So the > suggestion is whether, given that 2428 is at Proposed, > maybe it would be worth revising it, and the syntax for > EPRT and EPSV, to _permit_ use of a DNS name now and to > provide a clear extension path for a generic/stable > identifier. There is an issue with backwards compatibility here: Let's say we have a source host that has an implementation that allows EPRT and EPSV to use a name as well as an address. The destination host is a legacy host (meaning, a host implementing only 2428 as it is today, address only). How will the destination react when receiving an EPSV with a name instead of an address? More generically, how will a host react when receiving an EPSV with foo when foo is unknown? I am curious about the mechanism you envision to determine what kind of info is being passed. Michel.