目录 练习题 1. 显示当前的iptables规则 2. 允许所有来自192.168.1.0/24的TCP流量到本机的22端口（SSH） 3. 禁止所有来自10.0.0.0/8的ICMP流量 4. 允许所有出站流量 5. 拒绝所有来自外部的HTTP流量（80端口，tcp协议） 6. 删除INPUT链中的最后一条规则 7. 将默认策略设置为拒绝所有输入流量 9. 允许UDP流量从192.168.2.0/24到本机的53端口（DNS） 10. 保存当前的iptables规则到文件/etc/iptables/rules.v4（需要iptables-save命令） 11. 假设你有一个允许所有HTTP流量（80端口）的规则，但现在你只想允许来自192.168.0.0/16的HTTP流量，你应该如何修改这个规则？ 12. 你想要允许某个特定的IP地址（例如192.168.1.100）访问你服务器上所有的服务，应如何设置规则？
[ root@localhost ~]
Chain INPUT ( policy ACCEPT)
target prot opt source destination Chain FORWARD ( policy ACCEPT)
target prot opt source destination
DOCKER-USER all -- anywhere anywhere
DOCKER-ISOLATION-STAGE-1 all -- anywhere anywhere
ACCEPT all -- anywhere anywhere ctstate RELATED,ESTABLISHED
DOCKER all -- anywhere anywhere
ACCEPT all -- anywhere anywhere
ACCEPT all -- anywhere anywhere Chain OUTPUT ( policy ACCEPT)
target prot opt source destination Chain DOCKER ( 1 references)
target prot opt source destination
ACCEPT tcp -- anywhere 172.17 .0.3 tcp dpt:radan-httpChain DOCKER-ISOLATION-STAGE-1 ( 1 references)
target prot opt source destination
DOCKER-ISOLATION-STAGE-2 all -- anywhere anywhere
RETURN all -- anywhere anywhere Chain DOCKER-ISOLATION-STAGE-2 ( 1 references)
target prot opt source destination
DROP all -- anywhere anywhere
RETURN all -- anywhere anywhere Chain DOCKER-USER ( 1 references)
target prot opt source destination
RETURN all -- anywhere anywhere
[ root@localhost ~]
[ root@localhost ~]
Chain INPUT ( policy ACCEPT)
target prot opt source destination
ACCEPT tcp -- 192.168 .1.0/24 anywhere tcp dpt:ssh
[ root@localhost ~]
[ root@localhost ~]
Chain INPUT ( policy ACCEPT)
target prot opt source destination
ACCEPT tcp -- 192.168 .1.0/24 anywhere tcp dpt:ssh
DROP icmp -- 10.0 .0.0/8 anywhere
[ root@localhost ~]
[ root@localhost ~]
Chain OUTPUT ( policy ACCEPT)
target prot opt source destination
ACCEPT all -- anywhere anywhere
ACCEPT all -- anywhere anywhere
[ root@localhost ~]
[ root@localhost ~]
Chain INPUT ( policy ACCEPT)
target prot opt source destination
ACCEPT tcp -- 192.168 .1.0/24 anywhere tcp dpt:ssh
DROP icmp -- 10.0 .0.0/8 anywhere
REJECT tcp -- anywhere anywhere tcp dpt:http reject-with icmp-port-unreachable
iptables -D INPUT -1
注意：-1 表示删除最后一条规则。
[ root@localhost ~]
Chain INPUT ( policy ACCEPT)
num target prot opt source destination
1 ACCEPT tcp -- 192.168 .1.0/24 anywhere tcp dpt:ssh
2 DROP icmp -- 10.0 .0.0/8 anywhere
3 REJECT tcp -- anywhere anywhere tcp dpt:http reject-with icmp-port-unreachable
[ root@localhost ~]
[ root@localhost ~]
Chain INPUT ( policy ACCEPT)
target prot opt source destination
ACCEPT tcp -- 192.168 .1.0/24 anywhere tcp dpt:ssh
DROP icmp -- 10.0 .0.0/8 anywhere
iptables -P INPUT DROP
[ root@localhost ~]
iptables -A INPUT -s 192.168 .2.0/24 -p udp --dport 53 -j ACCEPT
[ root@localhost ~]
[ root@localhost ~]
Chain INPUT ( policy ACCEPT)
target prot opt source destination
ACCEPT tcp -- 192.168 .1.0/24 anywhere tcp dpt:ssh
DROP icmp -- 10.0 .0.0/8 anywhere
ACCEPT udp -- 192.168 .2.0/24 anywhere udp dpt:domain
iptables-save > /etc/iptables/rules.v4
[ root@localhost ~]
[ root@localhost ~]
[ root@localhost ~]
*nat
:PREROUTING ACCEPT [ 22 :2930]
:INPUT ACCEPT [ 22 :2930]
:OUTPUT ACCEPT [ 167 :14376]
:POSTROUTING ACCEPT [ 180 :15052]
:DOCKER - [ 0 :0]
-A PREROUTING -m addrtype --dst-type LOCAL -j DOCKER
-A OUTPUT ! -d 127.0 .0.0/8 -m addrtype --dst-type LOCAL -j DOCKER
-A POSTROUTING -s 172.17 .0.0/16 ! -o docker0 -j MASQUERADE
-A POSTROUTING -s 172.17 .0.3/32 -d 172.17 .0.3/32 -p tcp -m tcp --dport 8088 -j MASQUERADE
-A DOCKER -i docker0 -j RETURN
-A DOCKER ! -i docker0 -p tcp -m tcp --dport 8088 -j DNAT --to-destination 172.17 .0.3:8088
COMMIT
*mangle
:PREROUTING ACCEPT [ 37873 :257277525]
:INPUT ACCEPT [ 30364 :255656388]
:FORWARD ACCEPT [ 7509 :1621137]
:OUTPUT ACCEPT [ 25976 :1343905]
:POSTROUTING ACCEPT [ 33485 :2965042]
COMMIT
*raw
:PREROUTING ACCEPT [ 37873 :257277525]
:OUTPUT ACCEPT [ 25976 :1343905]
COMMIT
*security
:INPUT ACCEPT [ 30332 :255653088]
:FORWARD ACCEPT [ 7509 :1621137]
:OUTPUT ACCEPT [ 25976 :1343905]
COMMIT
*filter
:INPUT ACCEPT [ 344 :30199]
:FORWARD ACCEPT [ 0 :0]
:OUTPUT ACCEPT [ 0 :0]
:DOCKER - [ 0 :0]
:DOCKER-ISOLATION-STAGE-1 - [ 0 :0]
:DOCKER-ISOLATION-STAGE-2 - [ 0 :0]
:DOCKER-USER - [ 0 :0]
-A INPUT -s 192.168 .1.0/24 -p tcp -m tcp --dport 22 -j ACCEPT
-A INPUT -s 10.0 .0.0/8 -p icmp -j DROP
-A INPUT -s 192.168 .2.0/24 -p udp -m udp --dport 53 -j ACCEPT
-A FORWARD -j DOCKER-USER
-A FORWARD -j DOCKER-ISOLATION-STAGE-1
-A FORWARD -o docker0 -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
-A FORWARD -o docker0 -j DOCKER
-A FORWARD -i docker0 ! -o docker0 -j ACCEPT
-A FORWARD -i docker0 -o docker0 -j ACCEPT
-A OUTPUT -j ACCEPT
-A OUTPUT -j ACCEPT
-A DOCKER -d 172.17 .0.3/32 ! -i docker0 -o docker0 -p tcp -m tcp --dport 8088 -j ACCEPT
-A DOCKER-ISOLATION-STAGE-1 -i docker0 ! -o docker0 -j DOCKER-ISOLATION-STAGE-2
-A DOCKER-ISOLATION-STAGE-1 -j RETURN
-A DOCKER-ISOLATION-STAGE-2 -o docker0 -j DROP
-A DOCKER-ISOLATION-STAGE-2 -j RETURN
-A DOCKER-USER -j RETURN
COMMIT
先找到并删除旧的规则（假设它是INPUT链中的第3条规则）： iptables -D INPUT 3
iptables -A INPUT -s 192.168 .0.0/16 -p tcp --dport 80 -j ACCEPT
[ root@localhost ~]
[ root@localhost ~]
Chain INPUT ( policy ACCEPT)
target prot opt source destination
ACCEPT tcp -- 192.168 .1.0/24 anywhere tcp dpt:ssh
DROP icmp -- 10.0 .0.0/8 anywhere
ACCEPT udp -- 192.168 .2.0/24 anywhere udp dpt:domain
ACCEPT tcp -- 192.168 .0.0/16 anywhere tcp dpt:http
[ root@localhost ~]
[ root@localhost ~]
Chain INPUT ( policy ACCEPT)
target prot opt source destination
ACCEPT tcp -- 192.168 .1.0/24 anywhere tcp dpt:ssh
DROP icmp -- 10.0 .0.0/8 anywhere
ACCEPT udp -- 192.168 .2.0/24 anywhere udp dpt:domain
ACCEPT tcp -- 192.168 .0.0/16 anywhere tcp dpt:http
ACCEPT all -- 192.168 .1.100 anywhere
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