Linux Security Cookbook

2.17. Deleting Firewall Rules

Problem

You want to delete firewall rules, individually or all at once.

Solution

To delete rules en masse, also called flushing a chain, do the following:

For iptables:

# iptables -F [chain]

For ipchains:

# ipchains -F [chain]

To delete rules individually:

For iptables:

# iptables -D chain 
               rule_number

For ipchains:

# ipchains -D chain 
               rule_number

Discussion

Rules are numbered beginning with 1. To list the rules:

# iptables -L 

# ipchains -L

select one to delete (say, rule 4 on the input chain), and type:

# iptables -D INPUT 4

# ipchains -D input 4

If you’ve previously saved your rules and want your deletions to remain in effect after the next reboot, re-save the new configuration. [Recipe 2.19]

See Also

iptables(8), ipchains(8).