Date: Tue, 11 Apr 1995 16:22:10 -0400 (EDT) From: John Capo <jc@irbs.com> To: terry@cs.weber.edu (Terry Lambert) Cc: freebsd-current@freefall.cdrom.com (freebsd-current) Subject: Re: Missing telent login prompt Message-ID: <199504112022.QAA00482@irbs.com> In-Reply-To: <9504111818.AA00822@cs.weber.edu> from "Terry Lambert" at Apr 11, 95 12:18:32 pm
next in thread | previous in thread | raw e-mail | index | archive | help
Terry Lambert writes: > > > > > The missing telnet login prompt is timing related. A usleep(250000) > > > > anywhere in the child fixes it, at least for 50 login tests. > > > > > > When I telnet to any of the FreeBSD boxes here, the time it takes > > > for the login prompt to show up appears to be more or less random. > > > Sometimes it pops up right away, other times it can take up to 6 or 7 > > > seconds. Is this the same problem? > > > > No, the prompt fell on the floor. login is running and waiting > > for a user name. Terry says its a option negotiation problem. > > The reason the prompt is missing is because it was flushed by the > client who though it was still option negotiation time. Clearly, > a login prompt does not contain IsACommand characters. > > There are hacks in telnet to deal with BSD 4.2 and BSD 4.3 TCP/IP; > basically, the difference between the two is whether or not the > out of band data handling works. The telnet and telnetd decide > what type they are talking to based on option negotiation order. > > If the order is of one when it should be of the other, or if a > 4.2 implementation is talked to with someone who doesn't use the > order of operation hacks and starts using OOB for control messages, > then you get "dropped prompt" and other wierd behaviour. > > This is well known, and is in fact documented in the telnet code > that came with Net/2. > It worked with 1.1.5.1 so I guess we have lost the hacks to fix it. John Capo
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199504112022.QAA00482>