Install Tacacs Server Ubuntu

Tacacs+ is an open-standard protocol compatible across various networking equipment vendor platforms. Tacacs+ is a TCP based entirely new protocol used for AAA

1. Install the required packages

apt install build-essential flex yacc libwrap0-dev libpam0g-dev

2. Create folder for tacac configuration file on /etc/tacacs

mkdir /etc/tacacs

3. Download tacacs package from and extract tacacs package

wget <https://shrubbery.net/pub/tac_plus/tacacs-F4.0.4.28.tar.gz>
tar -xzvf tacacs-F4.0.4.28.tar.gz

4. Go to extracted folder, Now, we will configure and build the tac_plus packages on our server.

cd tacacs-F4.0.4.28
sudo ./configure --etcdir=/etc/tacacs
sudo make
sudo make install

4. Make tacacs log file and set permission

touch /var/log/tacacs.log
chmod 755 /var/log/tacacs.log

5. Make tacacs configuration file

nano /etc/tacacs/tac_plus.conf

add configuration edit file and add configuration

#Define tacacs server key
key = testing123

#Define tacacs server log location
accounting file = /var/log/tacacs.log
logging = local5

#Define groups that we shall add users to later

group = user {
        default service = permit
        login = file /etc/passwd
        service = exec {
                priv-lvl = 15
        }
}

#Defining users and assigning them to groups above

user = test {
        login = file /etc/passwd
        member = user
}

6. Start tacacs server

tac_plus -C /etc/tacacs/tac_plus.conf -d 128 -l /var/log/tac_plus.log

7. test tacacs auth

tactest -s {{server_ip}} -k {{key}} -u {{user}} -p {{password}}

------------------

SUMMARY STATISTICS

------------------

Total Commands  .....................  1
Successes  ..........................  1
Failures  ...........................  0
No Results  .........................  0
Time Taken for commands  ............  0,261 secs
Avg Possible Transactions/Second  ...  3
Network Time per command  ...........  0,107 secs
Total Network time  .................  0,107 secs
Sent Transactions/Second  ...........  3,3

Create Tacacs Service running on boot

nano /usr/bin/tacacs.sh

Add the script below

#!/bin/bash
tac_plus -C /etc/tacacs/tac_plus.conf -d 128 64 16 8 -l /var/log/tac_plus.log

And create service for running script on booting

nano /etc/systemd/system/tacacs.service

add

[Unit]
Description=Tacacs service
After=network.target

[Service]
ExecStart=/usr/bin/tacacs.sh
RemainAfterExit=true
Type=oneshot

[Install]
WantedBy=multi-user.target

reload and enable service tacacs

systemctl enable tacacs.service
systemctl daemon-reload

start tacacs service

systemctl start tacacs.service