How to use the -R[replace] option of the iptables.

pradiptart · 05-10-2013, 08:46 AM

Hi,

I am not able find a simple example of use of -R option of iptables.
what I got is ,it is possible to replace a previous rule to some other position.but how to do this.

e.g
Chain INPUT (policy ACCEPT)
target prot opt source destination
DROP all -- 10.0.0.2 anywhere
DROP all -- 10.0.0.24 anywhere

Chain FORWARD (policy ACCEPT)
target prot opt source destination

Chain OUTPUT (policy ACCEPT)
target prot opt source destination

I need the rule 2 to be the first one so ,how I will do that.

Kindly tell any answer regarding this.

Thanks

eSelix · 05-10-2013, 10:14 AM

-R option is for replacing rules, not for moving it. You want to make delete and then insert in proper position, like:

Code:

iptables -D INPUT 1
iptables -I INPUT 2 -s 10.0.0.2 -j DROP
#or
iptables -A INPUT -s 10.0.0.2 -j DROP

As these are probably only temporary, you need to change position of these rules in your firewall configuration file, where they are loaded at boot.