ufw command

`ufw` - program for managing a netfilter firewall

The ufw command (Uncomplicated Firewall) in Linux is a user-friendly front-end for managing iptables firewall rules. It simplifies setting up and controlling a firewall to secure your system by allowing or blocking network traffic.

Note: ufw is pre-installed on Ubuntu and some Debian-based systems. On others, install it with sudo apt install ufw or equivalent. Root privileges (via sudo) are required for most actions.

Usage: ufw [options] [command] [rule]

command: Action like enable, allow, deny.
rule: Specification of ports, services, or IPs.
options: Flags to modify behavior.

Common Commands Summary

Command	Description
`enable`	Activate the firewall
`disable`	Deactivate the firewall
`status`	Show current status and rules
`allow`	Permit traffic
`deny`	Block traffic
`delete`	Remove a rule
`reset`	Clear all rules

Examples

Enabling the Firewall

Turn on ufw to start enforcing rules.
```
sudo ufw enable
```
- Output: Firewall is active and enabled on system startup.
- Activates the firewall and sets it to start on boot.
Warning: Ensure you’ve allowed necessary services (e.g., SSH) before enabling to avoid locking yourself out.
Disabling the Firewall

Turn off ufw to stop filtering traffic.
```
sudo ufw disable
```
- Output: Firewall stopped and disabled on system startup.

Checking Status

See if ufw is active and what rules are in place.

sudo ufw status

Output (if inactive):
```
Status: inactive
```

Output (if active with rules):

Status: active
To                         Action      From
--                         ------      ----
22/tcp                     ALLOW       Anywhere
80/tcp                     ALLOW       Anywhere

Allowing Traffic

Use allow to permit incoming traffic on a port or service.

Example (Port):
```
sudo ufw allow 22
```
- Allows TCP traffic on port 22 (SSH).
Example (Service):
```
sudo ufw allow ssh
```
- Same as above, using the service name (from /etc/services).
Example (Specific IP):
```
sudo ufw allow from 192.168.1.100
```
- Allows all traffic from 192.168.1.100.
Denying Traffic

Use deny to block incoming traffic.
```
sudo ufw deny 23
```
- Blocks TCP traffic on port 23 (Telnet).

Deleting Rules

Remove a rule by referencing it.

sudo ufw delete allow 23

Deletes the rule allowing port 23.

List with Numbers:

sudo ufw status numbered

Output:

Status: active
    To                         Action      From
    --                         ------      ----
[ 1] 22/tcp                     ALLOW       Anywhere
[ 2] 80/tcp                     ALLOW       Anywhere

Delete by number:
```
sudo ufw delete 2
```

Resetting to Default

Clear all rules and disable ufw.
```
sudo ufw reset
```
- Output: Resetting all rules to installed defaults. Proceed? [y|n].
- Type y to confirm.

To get help related to the `ufw` command use `--help` option

$ ufw --help

Usage: ufw COMMAND

Commands:
 enable                          enables the firewall
 disable                         disables the firewall
 default ARG                     set default policy
 logging LEVEL                   set logging to LEVEL
 allow ARGS                      add allow rule
 deny ARGS                       add deny rule
 reject ARGS                     add reject rule
 limit ARGS                      add limit rule
 delete RULE|NUM                 delete RULE
 insert NUM RULE                 insert RULE at NUM
 prepend RULE                    prepend RULE
 route RULE                      add route RULE
 route delete RULE|NUM           delete route RULE
 route insert NUM RULE           insert route RULE at NUM
 reload                          reload firewall
 reset                           reset firewall
 status                          show firewall status
 status numbered                 show firewall status as numbered list of RULES
 status verbose                  show verbose firewall status
 show ARG                        show firewall report
 version                         display version information

Application profile commands:
 app list                        list application profiles
 app info PROFILE                show information on PROFILE
 app update PROFILE              update PROFILE
 app default ARG                 set default application policy

For more details, check the manual with man ufw

ufw - program for managing a netfilter firewall​

Examples​

To get help related to the ufw command use --help option​

`ufw` - program for managing a netfilter firewall

Examples

To get help related to the `ufw` command use `--help` option