if you dont specify a protocol it allows either tcp/udp

**ports** 
```
sudo ufw allow 22
sudo ufw allow 22/tcp
```

**ranges**
```
sudo ufw allow 6000:6007/tcp
sudo ufw allow 6000:6007/udp
```

**specific ip**
```
sudo ufw allow from 203.0.113.4
sudo ufw allow from 203.0.113.4 to any port 22
```

enable firewall `suod ufw enable`


## inquirey
`sudo ufw status numbered`
    pt@r710:~$ sudo ufw status numbered
    Status: active

        To                         Action      From
        --                         ------      ----
    [ 1] 22/tcp                     ALLOW IN    Anywhere
    [ 2] 5432                       ALLOW IN    Anywhere
    [ 3] 5440                       ALLOW IN    Anywhere
    [ 4] 10000                      ALLOW IN    Anywhere
    [ 5] 443/tcp                    ALLOW IN    Anywhere
    [ 6] 5433/tcp                   ALLOW IN    Anywhere
    [ 7] 22/tcp (v6)                ALLOW IN    Anywhere (v6)
    [ 8] 5432 (v6)                  ALLOW IN    Anywhere (v6)
    [ 9] 5440 (v6)                  ALLOW IN    Anywhere (v6)
    [10] 10000 (v6)                 ALLOW IN    Anywhere (v6)
    [11] 443/tcp (v6)               ALLOW IN    Anywhere (v6)
    [12] 5433/tcp (v6)              ALLOW IN    Anywhere (v6)