Find the IP address of the client in an SSH session

1) SSH_CLIENT
shows the address of the client system, the outgoing port number on the client system and the incoming port on the server.

Ex:
echo $SSH_CLIENT
10.10.10.211 63956  22

2) SSH_CONNECTION

Identifies the client and server ends of the connection.
The variable contains four space-separated values: client IP address,
client port number, server IP address, and server port number.

Ex:
echo $SH_CONNECTION
10.10.10.211 63956 172.16.32.11 22

3) SSH_TTY

This is set to the name of the tty (path to the device) associated
with the current shell or command.  If the current session has no tty,
this variable is not set.

Ex:
echo $SSH_TTY
/dev/pts/22

4) Set your own .bashrc

userIP=`echo $SSH_CLIENT | awk '{ print $1}'`

 if [ "$userIP" = "x.x.x.x" ]

 then

        echo "It's my machine IP"

        source /home/bob/.bashrc

 fi

Using this feature you can set your own .bashrc