iptables – rule deletion by number

Deletion is easiest if you know the rule number. Rather than counting down, it’s easiest to use -

iptables -nL –line-numbers

Which may show something like :

 

# iptables -nL --line-numbers
Chain INPUT (policy ACCEPT)
num  target     prot opt source               destination         
1    ACCEPT     udp  --  109.224.241.0/24     0.0.0.0/0            udp dpt:5060
2    ACCEPT     udp  --  109.224.241.0/24     0.0.0.0/0            udp dpt:4569
3    ACCEPT     udp  --  217.14.138.0/24      0.0.0.0/0            udp dpt:5060
4    ACCEPT     udp  --  217.14.138.0/24      0.0.0.0/0            udp dpt:4569
5    ACCEPT     udp  --  172.30.33.0/24       0.0.0.0/0            udp dpt:5060
6    ACCEPT     udp  --  172.30.33.0/24       0.0.0.0/0            udp dpt:4569
7    ACCEPT     udp  --  212.11.91.0/24       0.0.0.0/0            udp dpt:5060
8    ACCEPT     udp  --  212.11.91.0/24       0.0.0.0/0            udp dpt:4569
9    ACCEPT     udp  --  212.11.64.0/19       0.0.0.0/0            udp dpt:5060
10   ACCEPT     udp  --  212.11.64.0/19       0.0.0.0/0            udp dpt:4569
11   ACCEPT     udp  --  77.240.48.0/20       0.0.0.0/0            udp dpt:5060
12   ACCEPT     udp  --  77.240.48.0/20       0.0.0.0/0            udp dpt:4569
13   LOG        udp  --  0.0.0.0/0            0.0.0.0/0            udp dpt:4569 LOG flags 0 level 4 prefix "AsteriskHack:"
14   DROP       udp  --  0.0.0.0/0            0.0.0.0/0            udp dpt:4569
15   LOG        udp  --  0.0.0.0/0            0.0.0.0/0            udp dpt:5060 LOG flags 0 level 4 prefix "AsteriskHack:"
16   DROP       udp  --  0.0.0.0/0            0.0.0.0/0            udp dpt:5060

Chain FORWARD (policy ACCEPT)
num  target     prot opt source               destination         

Chain OUTPUT (policy ACCEPT)
num  target     prot opt source               destination

(The above is my crude firewall to stop anyone from hacking into my asterisk server).

I could then delete e.g rule 10 (212.11.64.0/0/19, destination port 4569) with :


iptables -D INPUT 10

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