Path: utzoo!attcan!uunet!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!know!samsung!xylogics!bu.edu!snorkelwacker!bloom-beacon!athena.mit.edu!jik From: jik@athena.mit.edu (Jonathan I. Kamens) Newsgroups: comp.protocols.tcp-ip Subject: Re: Multiple versions of TALK? (was: Major bug in TALK on WIN/TCP for VMS) Message-ID: <1990Jul3.181759.14369@athena.mit.edu> Date: 3 Jul 90 18:17:59 GMT References: <28296.2689c707@vaxb.acs.unt.edu> <4875@sunquest.UUCP> Sender: news@athena.mit.edu (News system) Reply-To: jik@athena.mit.edu (Jonathan I. Kamens) Organization: Massachusetts Institute of Technology Lines: 43 In article , towfiq@interlan.Interlan.COM (Mark Towfigh) writes: |> I know this is true -- it's a problem because there are incompatible |> versions of TALK out there. Specifically, it seems there was a change |> between the 4.2BSD talk/talkd and the one in 4.3BSD. I have a few |> questions: does the current TALK daemon support both the old and new |> versions? No. You have to run two different versions of talkd, one on the port reserved for the old talk protocol, and one on the port reserved for the new talk protocol. On our system, old talk is 517 (with the service name "talk"), and new talk is 518 (with the service name "ntalk"). If you don't have the right daemons running on the right ports, then talk clients are going to have trouble conversing with your machine. |> And what about the client? Nope, the old talk client knows how to talk only to the old talk port, and the new talk client knows how to talk only to the new talk port. Or, at least, that's how things *should* work, but alas, we live in an imperfect world.... |> As far as I can make out, the |> new talkd can tell the difference between the two protocols, and when |> a remote user requests a connection, the local TALK daemon figures out |> whether they are TALKing 4.2-style or 4.3-style, and then tells the |> local user to run one of two programs, either /usr/ucb/talk or |> /usr/old/talk. No, this isn't how it works, or at least not how it appears to be set up in 4.3BSD. There are two different talkd programs (/etc/talkd and /etc/ntalkd is what we've got them named, but I don't know how universal that is). The hard-coded client name in the old talk daemon is /usr/ucb/talk.old or /usr/old/talk, and the hard-coded client name in the new talk daemon is /usr/ucb/talk. The new talk daemon and the old talk daemon don't know about each other, and don't know about each other's protocols. Jonathan Kamens USnail: MIT Project Athena 11 Ashford Terrace jik@Athena.MIT.EDU Allston, MA 02134 Office: 617-253-8495 Home: 617-782-0710