secure shell – nixCraft

Debian Linux Install OpenSSH SSHD Server

January 11, 2012January 11, 2012in Debian / Ubuntu last updated January 11, 2012

How do I install OpenSSH sshd server under Debian GNU/Linux operating systems?

Remote Shutdown of a Linux / Unix Computer From MS-Windows

July 13, 2011July 13, 2011in Linux, Windows last updated July 13, 2011

How do I shutdown remote Linux or UNIX system from MS-Windows system?

Linux: Block Port With IPtables

December 10, 2010August 25, 2016in CentOS, Debian / Ubuntu, Iptables, Linux, RedHat and Friends, Suse last updated August 25, 2016

How do I block port number with iptables under Linux operating systems?

Start / Stop / Restart Apache Web Server Via SSH

February 14, 2010February 14, 2011in Apache, Linux last updated February 14, 2011

How do I start / stop or restart Apache web sever via SSH (secure shell) under Linux or UNIX operating systems?
Continue reading “Start / Stop / Restart Apache Web Server Via SSH”

How to: Ubuntu / Debian Linux Regenerate OpenSSH Host Keys

June 15, 2008February 16, 2017in Debian / Ubuntu, Linux, Networking, Openbsd, Package Management, RedHat and Friends, Ubuntu Linux last updated February 16, 2017

How do I regenerate OpenSSH sshd server host keys stored in /etc/ssh/ssh_host_* files? Can I safely regenerate ssh host keys using remote ssh session as my existing ssh connections shouldn’t be interrupted on Debian or Ubuntu Linux? How do I regenerate new ssh server keys?

HP-UX start or stop / restart OpenSSH SSHD service

July 17, 2007July 17, 2007in HP-UX Unix, Security, UNIX last updated July 17, 2007

Q. Iâ€™ve HP-UX installed on my HP UX UNIX server. But Iâ€™m not able to start or restart the OpenSSH ssh server. How do I stop or restart sshd under HP-UX?
A. HP-UX Secure Shell uses Pluggable Authentication Module for password authentication. Server configuration file is located at /opt/ssh/etc/sshd_config.

HP-UX SSHD System Startup and Shutdown script:

/sbin/init.d/secsh {start|stop}

System startup configuration file

/etc/rc.config.d/sshd

Stop HP UX SSH Service

Type the command:
# /sbin/init.d/secsh stop

Start HP UX SSH Service

Type the command:
# /sbin/init.d/secsh start

Configure rsh so that is does not prompt for a password

May 1, 2006August 6, 2007in BASH Shell, CentOS, FreeBSD, HP-UX Unix, Linux, RedHat and Friends, Solaris-Unix, UNIX last updated August 6, 2007

Both rsh or rlogin prompt for a password. All you need to do is open /etc/hosts.equiv file on host system and add entries for all hosts you would like use without password .

This file list of hosts and users that are granted “trusted” r (rsh/rloging) command access to your system without supplying a password.

$ cat /etc/hosts.equiv

Output:

job1.ha1.nixcraft.com
job2.ha1.nixcraft.com
job3.ha1.nixcraft.com

In above file job1, job2, job3 hosts can connect without a password.

Caution: R (rsh/rlogin) commands are very insecure if possible switch to secure shell (ssh). You can configure ssh so that is does not prompt for a password.