tldr/pages/linux/ufw-deny.md

ufw deny

Block traffic through the firewall. More information: https://manned.org/ufw.

• Deny all traffic on a port:

sudo ufw deny {{port}}

• Deny traffic for a protocol on a port:

sudo ufw deny {{port}}/{{protocol}}

• Deny incoming traffic for a protocol and add a comment for documentation:

sudo ufw deny in {{protocol}} comment '{{comment}}'

• Deny all traffic from a source address:

sudo ufw deny from {{source_address}}

• Deny all incoming traffic from the subnet 192.168.13.0/24:

sudo ufw deny from 192.168.13.0/24

• Deny UDP traffic from 192.168.1.12 to 192.168.1.100 on port 8080:

sudo ufw deny from 192.168.1.12 to 192.168.1.100 port 8080 proto udp

• Deny all incoming IGMP traffic to 192.168.1.100 on the eth0 interface:

sudo ufw deny in on eth0 to 192.168.1.100 proto igmp