To delete a prerouting rule from the iptables firewall in Linux, you can use the following command:
iptables -t nat -D PREROUTING -p PROTOCOL -i INTERFACE -d DESTINATION -j TARGET
Replace "PROTOCOL" with the protocol of the traffic (e.g., tcp, udp, icmp), "INTERFACE" with the name of the interface (e.g., eth0, wlan0), "DESTINATION" with the destination IP address or network, and "TARGET" with the action to be taken (e.g., ACCEPT, DROP).
For example, to delete a prerouting rule that redirects incoming traffic on the "eth0" interface to the IP address "192.168.1.100" using the TCP protocol, you can use the following command:
iptables -t nat -D PREROUTING -p tcp -i eth0 -d 192.168.1.100 -j ACCEPT
Note: The above command assumes that the prerouting rule exists in the iptables configuration. If the rule doesn't exist, the command will fail. To view the current prerouting rules, you can use the "iptables -t nat -L" command.
Additionally, make sure to save the iptables configuration after deleting the rule by running the following command:
service iptables save
This will persist the changes across system reboots.