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SSH Script

Here’s my custom ssh script named login.sh using multiple arguments. 

#!/bin/bash
if [ $# -eq 0 ]
  then
    echo 'no server supplied'
        exit 1
fi
INPUT=$2
case "$INPUT" in
  abc)
    ssh user1@$1
    ;;
  def)
    ssh user2@$1
    ;;
  *)
    ssh user3@$1
    ;;
esac

How to use with expected outputs.

./login.sh
no server supplied
./login.sh server3 abc
ssh user1@server3
./login.sh server2 def
ssh user2@server2
./login.sh server1
ssh user3@server1

Increase SSH Timeout

Here’s how to keep your SSH timeout alive for a longer period.

Edit /etc/ssh/sshd_config. Adjust interval and count max.

ClientAliveInterval 1200
ClientAliveCountMax 3

ClientAliveInterval is set to 1200 and ClientAliveCountMax is set to the default which is 3. This means unresponsive SSH clients will be disconnected after approximately 3600 seconds or 1 hour.

AWS LightSail Restrict IP Address

AWS LightSail now has the ability to restrict IP addresses in their firewall rules. LightSail instances can now be secured by limiting firewall rules from an IP CIDR block or a single IP address. For example, you can restrict who can SSH into your instance by limiting it to just your IP address, so only you can SSH into your machine. Another feature AWS added in their LightSail firewall is support for ping, which could be helpful for monitoring and checks.