Summary:Telnet negotiation fails on 2.5.1

From: Vijay Telang (
Date: Tue Mar 04 1997 - 22:53:00 CST


I received 3 replies. I think the problem is due to a tightening of the
way Solaris 2.5.1 handles Telnet options. Prior to this release it was
acceptable not to respond to options not supported by our emulator. now
Solaris seems to stop the negotiation if it does not get a TCWONT
response. Hence we have now modified our emulator to behave accordingly.

Thanks to all who replied. The reponses are as follows.

Reply from :

- Check for missing libraries

   ldd /opt/fwtk/bin/netacl

- Change inetd.conf entry for telnet as follows :

   Replace /opt/fwtk/bin/netacl with /usr/sbin/in.telnetd

   Then do a kill -1 on inetd
- Use snoop to do further investigation.

--- I tried all these suggestions without luck.

Reply from Casper Dik <casper@holland.Sun.COM

The new telnet client that coems with 2.5 and later supports more telnet

It seems the FWTK doesn't handle those (in which case it should respoind
with "WONT".

The 2.4 telnet binary should work fine.

--- I think you are right.

Reply from Bob Woodward <> :
I'm not an expert but you do have a pattern there. From the SUN 1000,
what type of terminal settings are being set? It almost looks like the
..profile/.cshrc settings are not 'matching' to the type of terminal
emulation your telnet session is trying to come in as. Example would be
you've set the telnet to go in as 'ansi' but your SUN 1000 either
doesn't have this defined and/or your defaults are set to something
'unique/special'. I'd be digging into the 'termcap & terminfo' book
from O'Reilly & Associates.

--- Your suggestion will be helpful to fix another problem that I have
about the changed behaviour of <CTRL>C.

Original question :

>We have a terminal emulation program on a PC which starts a telnet
>session on a SPARC 1000 (Solaris 2.5.1) and emulates a vt100. This works
>fine on a SPARC 2000 running Solaris 2.4. It used to work on the SPARC
>1000 with Solaris 2.3 before we did the upgrade to 2.5.1.
>This problem occurs only with this emulation program. Telnets from
>anywhere else is OK.
>I checked the inetd.conf file and we are using FWTK. Is there a new
>version for 2.5.1 ??
>When the emulation program is run in debug mode, it starts Telnet
>negotiation and produces the following output :
>[14:39:29.94] ------------- BUG STARTED -------------
>SwitchSession(22) sessno=-1
>[14:39:33.73] Attempting connection to host01
>[14:39:33.78] connect() returned 1
>[14:39:34.6] rcvmsg() socket=1 length=15
>[14:39:34.6] sendbuf() socket=1 length=3
><--(1) DO o(31)
>set_option(31) invalid case
><--(1) DO o(35)
>set_option(35) invalid case
><--(1) DO o(39)
>set_option(39) invalid case
><--(1) DO o(36)
>set_option(36) invalid case
>handleTELNET() returned 0
>[14:40:25.91] ENDBUG Userid=Vijay Telang
>Any clues will be much appreciated. Thanks in advance.

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