Firewall on OVH Vps server

 Posted on March 30, 2018  |  0 minutes (0 words)

Installing and configuring the Uncomplicated Firewall

All the commands are executed by the root user.

Installation

apt install ufw

Configuration

Before starting the firewall we have to allow ssh traffic or we will close ourself out.

# if ssh is still on port 22
ufw allow ssh
# if it is on a custom port
ufw allow 2222/tcp

Add a few port for http and https

ufw allow 80/tcp
ufw allow 443/tcp

Check the rules and start the firewall

ufw show added
ufw enable
# check the status
ufw status
# with a bit more info
ufw status verbose

Done. It was uncomplicated.

Remove a rule

View a numbered list of rules and remove the rule using the index

ufw status numbered
  Status: active

     To                         Action      From
     --                         ------      ----
  [ 1] 2222/tcp                   ALLOW IN    Anywhere
  [ 2] 80                         ALLOW IN    Anywhere
  [ 3] 443                        ALLOW IN    Anywhere
  [ 4] Anywhere                   ALLOW IN    94.81.51.199 9000
  [ 5] 2222/tcp (v6)              ALLOW IN    Anywhere (v6)
  [ 6] 80 (v6)                    ALLOW IN    Anywhere (v6)
  [ 7] 443 (v6)                   ALLOW IN    Anywhere (v6)

ufw delete 4

More

A few other commands that can be useful

# Port ranges
ufw allow 1000:2000/tcp
ufw allow 1000:2000/udp
# IP address
ufw allow from 15.15.15.51
# Subnet
ufw allow from 15.15.15.0/24
# Deleting Rules
ufw delete allow ssh
# Deny an ip
ufw deny from 15.15.15.51
# Deny a subnet
ufw deny from 15.15.15.0/24