LinuxQuestions.org - SSH Help - How to limit concurrent logins by a user

Thanks for the reply, however I wasn't very successful :(

I uncommented MaxStartups in /etc/ssh/sshd_config and set it to "1", and restarted sshd, but I was still able to login multiple times.

Code:

$ w

 19:00:13 up 31 days, 21:44,  4 users,  load average: 0.00, 0.00, 0.00

USER    TTY      FROM              LOGIN@  IDLE  JCPU  PCPU WHAT

root    pts/0    7800gt          18:56  32.00s  0.32s  0.32s -bash

breakawa pts/5    7800gt          18:59  13.00s  0.21s  0.21s -bash

breakawa pts/3    7800gt          18:59  25.00s  0.20s  0.20s -bash

root    pts/6    7800gt          19:00    0.00s  0.24s  0.01s w

Here is my sshd_conf file:

Code:

#        $OpenBSD: sshd_config,v 1.73 2005/12/06 22:38:28 reyk Exp $



# This is the sshd server system-wide configuration file.  See

# sshd_config(5) for more information.



# This sshd was compiled with PATH=/usr/local/bin:/bin:/usr/bin



# The strategy used for options in the default sshd_config shipped with

# OpenSSH is to specify options with their default value where

# possible, but leave them commented.  Uncommented options change a

# default value.



Port 22

#Protocol 2,1

Protocol 2

#AddressFamily any

#ListenAddress 0.0.0.0

#ListenAddress ::



# HostKey for protocol version 1

#HostKey /etc/ssh/ssh_host_key

# HostKeys for protocol version 2

#HostKey /etc/ssh/ssh_host_rsa_key

#HostKey /etc/ssh/ssh_host_dsa_key



# Lifetime and size of ephemeral version 1 server key

#KeyRegenerationInterval 1h

#ServerKeyBits 768



# Logging

# obsoletes QuietMode and FascistLogging

#SyslogFacility AUTH

SyslogFacility AUTHPRIV

#LogLevel INFO



# Authentication:



#LoginGraceTime 2m

#PermitRootLogin yes

#StrictModes yes

#MaxAuthTries 6



#RSAAuthentication yes

#PubkeyAuthentication yes

#AuthorizedKeysFile        .ssh/authorized_keys



# For this to work you will also need host keys in /etc/ssh/ssh_known_hosts

#RhostsRSAAuthentication no

# similar for protocol version 2

#HostbasedAuthentication no

# Change to yes if you don't trust ~/.ssh/known_hosts for

# RhostsRSAAuthentication and HostbasedAuthentication

#IgnoreUserKnownHosts no

# Don't read the user's ~/.rhosts and ~/.shosts files

#IgnoreRhosts yes



# To disable tunneled clear text passwords, change to no here!

#PasswordAuthentication yes

#PermitEmptyPasswords no

PasswordAuthentication yes



# Change to no to disable s/key passwords

#ChallengeResponseAuthentication yes

ChallengeResponseAuthentication no



# Kerberos options

#KerberosAuthentication no

#KerberosOrLocalPasswd yes

#KerberosTicketCleanup yes

#KerberosGetAFSToken no



# GSSAPI options

#GSSAPIAuthentication no

GSSAPIAuthentication yes

#GSSAPICleanupCredentials yes

GSSAPICleanupCredentials yes



# Set this to 'yes' to enable PAM authentication, account processing, 

# and session processing. If this is enabled, PAM authentication will 

# be allowed through the ChallengeResponseAuthentication mechanism. 

# Depending on your PAM configuration, this may bypass the setting of 

# PasswordAuthentication, PermitEmptyPasswords, and 

# "PermitRootLogin without-password". If you just want the PAM account and 

# session checks to run without PAM authentication, then enable this but set 

# ChallengeResponseAuthentication=no

#UsePAM no

UsePAM yes



# Accept locale-related environment variables

AcceptEnv LANG LC_CTYPE LC_NUMERIC LC_TIME LC_COLLATE LC_MONETARY LC_MESSAGES 

AcceptEnv LC_PAPER LC_NAME LC_ADDRESS LC_TELEPHONE LC_MEASUREMENT 

AcceptEnv LC_IDENTIFICATION LC_ALL

#AllowTcpForwarding yes

#GatewayPorts no

#X11Forwarding no

X11Forwarding yes

#X11DisplayOffset 10

#X11UseLocalhost yes

#PrintMotd yes

#PrintLastLog yes

#TCPKeepAlive yes

#UseLogin no

#UsePrivilegeSeparation yes

#PermitUserEnvironment no

#Compression delayed

#ClientAliveInterval 0

#ClientAliveCountMax 3

#ShowPatchLevel no

#UseDNS yes

#PidFile /var/run/sshd.pid

MaxStartups 1

#PermitTunnel no



# no default banner path

#Banner /some/path



# override default of no subsystems

Subsystem        sftp        /usr/libexec/openssh/sftp-server

Am I missing something here?