topic SSH connection number problem in Operating System - Linux

SSH connection number problem

ronald tang — Fri, 29 Dec 2006 13:14:31 GMT

I have a HP itanium box with OS ver11.23, it only allows 2 SSH connections in currently(the 3rd will be refused), I want to change this settings, but when I looked at SSH configuration file, I did not find any parameter or directive associated with this setting.

Please help.

Ronald

Re: SSH connection number problem

Ragu_3 — Sun, 31 Dec 2006 04:10:57 GMT

"MaxStartups" is the directive for supporting concurrent connections in your "sshd_config" file.

MaxStartups specifies the maximum number of concurrent connections to the SSH daemon. The default value might be 2.

Re: SSH connection number problem

Steven E. Protter — Mon, 01 Jan 2007 03:41:31 GMT

Shalom,

This being an HP-UX system, there are kernel parameters that need to be checked.

dtvitan1:/# kctune | grep tel
nstrtel 60 Default

Someone may have lowered this figure, which is not dynamic and requires a system boot.

Check:
/var/adm/syslog/syslog.log
There may be an error message there that is helpful.

After changing ssh_config or sshd_config
/sbin/init.d/secsh stop
/sbin/init.d/secsh start

SEP

Re: SSH connection number problem

ronald tang — Wed, 03 Jan 2007 10:35:09 GMT

Hi,

I looked up the syslog.log, found the following messages:

Dec 29 14:27:11 webdev03 sshd[17507]: Accepted keyboard-interactive/pam for rtang from 10.97.2.92 port 1645 ssh2
Dec 29 14:27:29 webdev03 sshd[17532]: Accepted keyboard-interactive/pam for rtang from 10.97.2.92 port 1646 ssh2
Dec 29 14:29:04 webdev03 sshd[17554]: Accepted keyboard-interactive/pam for rtang from 10.97.2.92 port 1647 ssh2
Dec 29 14:29:04 webdev03 sshd[17562]: fatal: PAM: pam_open_session(): Can not make/remove entry for session

It is sounds the PAM dosen't allow the 3rd session, but I don't know how to config PAM.

Re: SSH connection number problem

Denver Osborn — Wed, 03 Jan 2007 21:14:14 GMT

Have a look at the /etc/default/security file for an NUMBER_OF_LOGINS_ALLOWED entry. You probably have this set at "2". This is system wide, increase it if needed.

-denver

Re: SSH connection number problem

ronald tang — Thu, 04 Jan 2007 16:09:08 GMT

Hi Denver,

I looked up the /etc/default/security, the "
NUMBER_OF_LOGINS_ALLOWED" was set to 1, after I changed it to 0 (allow any times login), it is working fine.

But I still don't understand why i can have 2 connections before while the settings was (NUMBER_OF_LOGINS_ALLOWED=1).

Thank you all for help.