topic ipv6 telnet connection closed in Operating System - HP-UX

ipv6 telnet connection closed

Tan Eu Soon — Wed, 08 Jan 2003 07:26:43 GMT

I have a HP11i, AIX5L and Solaris 8 machine all configured with ipv6. From the HP machine, I'm able to telnet to the solaris machine's ipv6 address and login. However, on the solaris machine I'm getting "Connection closed by foreign host" but using rlogin to connect to the HP's ipv6 address was successful. There were no login issue on the AIX.

The following error was noted in my syslog.log:

"Telnetd[22785]: Telnet Port Identification Feature Not Available For IPV6".

What could be wrong on my HP-UX11i setup ?

Re: ipv6 telnet connection closed

Jerome Baron — Wed, 08 Jan 2003 09:04:45 GMT

Hi,

The problem is caused by an unanticipated response
from an IPV6 Sun client during the telnet negotiation, where
the Sun IPV6 telnet client agrees to provide TELOPT_ENV (see
option #36 in telnet.h). HP-UX telnetd only expects TELOPT_ENV
from IPV4 telnet clients such as the DTC.

Sun refers to option 36 in their /usr/include/arpa/telnet.h as

#define TELOPT_OLD_ENVIRON 36 /* Old - Environment variables */

When connecting to hp-ux from IPV4 client, Sun telnet provides a
NULL for board id, port id as subnegotiation values
(TELQUAL_USERVAR) but this case is handled in telnetd and the
connection proceeds. However, when hp-ux telnetd runs in the IPV6
case, there is no allowance for TELOPT_ENV negotiation with an IPV6
peer, so the connection is terminated by telnetd.

This problem seem fix in PHNE_24829.

Regards,
Jerome

Re: ipv6 telnet connection closed

Tan Eu Soon — Thu, 09 Jan 2003 01:10:36 GMT

Thank-U very much Jerome. The problem has been resolved.