Linux SSH connection settings

suselinux11 SSH settings. Close the root user connection, using the sshd user connection. The root user is then redirected through the sshd user.

1. Set/etc/ssh/sshd_config

#vi/etc/ssh/sshd_config

Port 22 (using 22 ports)

Clientaliveinterval 300 (logs a timeout after connecting 300s)
Clientalivecountmax 0 (if the client is found to be not corresponding, then a timeout is determined, this parameter sets the number of times the timeout is allowed)

Allowusers sshd (only sshd users log on after server hardening)

2. Adding sshd to a user group

(1)/etc/pam.d/su file see if the following sentence is set to work.
Auth Required pam_whell.so Use_uid

(2) Note su_wheel_only Yes

Vi/etc/login.defs
#SU_WHEEL_ONLY Yes

(3)/BIN/SU's permission is '-rwsr-xr-x '

Ll/bin/su

-rwsr-xr-x 1 root root 40016 Mar 2013/bin/su

3. Su-root password is correct, error su:incorrect password

(1) Because/etc/pam.d/su in auth required pam_whell.so Use_uid

(2) Need to add sshd user to Whell Group

#usermod sshd-g Whell

4. Turn off the firewall

(1) Temporarily shut down the firewall

Rcsusefirewall2_setup stop

Rcsusefirewall2_init stop

(2) Permanently shut down the firewall

Chkconfig Susefirewall2_setup off

Chkconfig Susefirewall2_init off

5., Start SSH

/etc/init.d/sshd start

Chkconfig sshd on (SSH join auto-start)

Linux SSH connection settings