[리눅스]iptables 설정 변경하기(끼워넣기)

iptables 정책 확인 

iptables 허용 정책 추가

iptables -I INPUT -p tcp -s 0.0.0.0/0 --dport 22021 -j ACCEPT
iptables -I INPUT -p tcp -s 0.0.0.0/0 --dport 22022 -j ACCEPT
iptables -I INPUT -p tcp -s 0.0.0.0/0 --dport 22023 -j ACCEPT
iptables -I INPUT -p tcp -s 0.0.0.0/0 --dport 22024 -j ACCEPT
iptables -I INPUT -p tcp -s 0.0.0.0/0 --dport 22025 -j ACCEPT
iptables -I INPUT -p tcp -s 0.0.0.0/0 --dport 22026 -j ACCEPT

위 명령어로 순서대로 실행하게 되면 한번 실행될 때마다 첫 번째 자리에 들어가기 때문에 순서가 반대로 들어가게 된다.

[root@centos79 ~]# iptables -nL
Chain INPUT (policy ACCEPT)
target     prot opt source               destination
ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0            tcp dpt:22026
ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0            tcp dpt:22025
ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0            tcp dpt:22024
ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0            tcp dpt:22023
ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0            tcp dpt:22022
ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0            tcp dpt:22021

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination

iptables 허용 정책 삭제

-D : 삭제 옵션

INPUT 1 : INPUT 정책의 첫번째 정책 삭제

INPUT 3 : INPUT 정책의 세번째 정책 삭제

-F : 모든 규칙 삭제

[root@centos79 ~]# iptables -D INPUT 1
[root@centos79 ~]# iptables -nL
Chain INPUT (policy ACCEPT)
target     prot opt source               destination
ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0            tcp dpt:22025
ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0            tcp dpt:22024
ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0            tcp dpt:22023
ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0            tcp dpt:22022
ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0            tcp dpt:22021

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination

[root@centos79 ~]# iptables -D INPUT 3
[root@centos79 ~]# iptables -nL
Chain INPUT (policy ACCEPT)
target     prot opt source               destination
ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0            tcp dpt:22025
ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0            tcp dpt:22024
ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0            tcp dpt:22022
ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0            tcp dpt:22021

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination

[root@centos79 ~]# iptables -F
[root@centos79 ~]# iptables -nL
Chain INPUT (policy ACCEPT)
target     prot opt source               destination

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination

iptables 허용 정책 원하는 위치에 추가하기

삭제와 같이 INPUT 뒤에 몇번째 자리에 들어갈지 숫자를 주게 되면 원하는 위치에 넣을 수 있다. 

iptables -I INPUT 1 -p tcp -s 0.0.0.0/0 --dport 22021 -j ACCEPT
iptables -I INPUT 2 -p tcp -s 0.0.0.0/0 --dport 22022 -j ACCEPT
iptables -I INPUT 3 -p tcp -s 0.0.0.0/0 --dport 22023 -j ACCEPT
iptables -I INPUT 4 -p tcp -s 0.0.0.0/0 --dport 22024 -j ACCEPT
iptables -I INPUT 5 -p tcp -s 0.0.0.0/0 --dport 22025 -j ACCEPT
iptables -I INPUT 6 -p tcp -s 0.0.0.0/0 --dport 22026 -j ACCEPT

[root@centos79 ~]# iptables -nL
Chain INPUT (policy ACCEPT)
target     prot opt source               destination
ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0            tcp dpt:22021
ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0            tcp dpt:22022
ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0            tcp dpt:22023
ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0            tcp dpt:22024
ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0            tcp dpt:22025
ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0            tcp dpt:22026

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination