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Adding and Removing sshd instances on CentOS 6

Submitted by Igor on April 20, 2019 – 8:24 pm

This is a process and a couple of script to allow you to setup an additional sshd service on an alternate port.

The two scripts below are for CentOS/RHEL 6, but they can be easily adapted for the current versions. The new script will prompt you for the instance name and port. It will verify that both a unique. The script will also add iptables rule, if you are running it. If you’re using selinux, you will need to make some additional changes manually.

The del script will prompt you for the name of the instance you want to delete.

You can download the add script here, and the del script here.

Sample output of add

[root@ncc1711:/usr/sbin] # /var/adm/bin/sshd_new_instance.sh
Name the new sshd instance: test
Specify the port for sshd-test: 23165
iptables: Saving firewall rules to /etc/sysconfig/iptables:[  OK  ]
Stopping sshd:                                             [  OK  ]
Starting sshd:                                             [  OK  ]
Starting sshd-test:                                        [  OK  ]
sshd-test is active:
COMMAND     PID USER   FD   TYPE DEVICE SIZE/OFF NODE NAME
sshd-test 11394 root    3u  IPv4  50522      0t0  TCP *:23165 (LISTEN)
sshd-test 11394 root    4u  IPv6  50524      0t0  TCP *:23165 (LISTEN)

Sample output of del

[root@ncc1711:/usr/sbin] # /var/adm/bin/sshd_del_instance.sh
Name the sshd instance to delete: test
Stopping sshd-test:                                        [  OK  ]
Stopping sshd:                                             [  OK  ]
Starting sshd:                                             [  OK  ]
sshd-test is off
iptables: Saving firewall rules to /etc/sysconfig/iptables:[  OK  ]