Here is an example to delete rule with line number 3 in INPUT chain. Once you have the line number of each rule, you can mention it in iptables command. $ sudo iptables -L -line-numbersġ ACCEPT all - anywhere anywhere ctstate RELATED,ESTABLISHEDģ DROP all - anywhere anywhere ctstate INVALIDĤ UDP udp - anywhere anywhere ctstate NEW You can view each rule’s line number with the following command. You can also delete iptables rules by mentioning the chain and line number. $ sudo iptables -D INPUT -m conntrack -ctstate INVALID -j DROPĮach iptable rule has a serial number known as line number. Here is an example to delete rule that drops invalid incoming packets. You can easily delete iptables rules using -D option followed by rule specification. Now that we have seen different ways to view iptables rules, let us learn how to delete them. destination: Destination IP address or subnet of the traffic, or anywhere.source: Source IP address or subnet of the traffic, or anywhere.opt: Rarely used, this column indicates IP options.prot: protocol such as tcp, udp, icmp, or all.target: If a packet matches the rule, the target specifies what should be done with it – whether it should be accepted, dropped, logged, or sent to another chain.Here is what the different columns in about output mean REJECT all - anywhere anywhere reject-with icmp-proto-unreachable REJECT tcp - anywhere anywhere reject-with tcp-reset REJECT udp - anywhere anywhere reject-with icmp-port-unreachable ICMP icmp - anywhere anywhere ctstate NEW TCP tcp - anywhere anywhere tcp flags:FIN,SYN,RST,ACK/SYN ctstate NEW OutputĪCCEPT all - anywhere anywhere ctstate RELATED,ESTABLISHEDĭROP all - anywhere anywhere ctstate INVALID If you want to view only INPUT chain rules, you can specify the chain name after -L option in iptables. You can also view all iptables rules as a table, with the following command. Here is an example to view rules in TCP chain. If you want to list a specific rule chain such as INPUT, OUTPUT, TCP, etc. Open terminal and run the following command to list all active iptables rules. We need to able to clearly identify and specify while rules are to be deleted.
First we will look at the different ways to list existing iptables rules. Here are the different ways to delete or remove existing iptables rules. In this article, we will learn how to delete iptables rules. Sometimes you may need to delete one or more rules in iptables. It consists of a set of rules and rule chains that are used by operating system to block/allow traffic. Iptables is a firewall in Linux that allows you to control incoming and outgoing traffic.
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