iptables
http://linux.vbird.org/linux_server/0250simple_firewall.php#netfilter
iptables 是利用封包过滤机制, 分析封包的表头资料,根据表头资料定义的规则来决定是否可以进入主机或者被丢弃.
刚才在服务器上练习的时候把自己给屏蔽了,提醒大家拿其他同学的ip做练习,哈哈.
$iptables [-t tables] [-L] [-nv]
-t: 后面接table, 例如nat 或者filter,如果省略此项目,则使用预设的filter
-L:列出目前的table的规则
-n: 不进行IP与HOSTNAME的反查
-v: 列出更多的信息,包括通过该规则的封包总位元数等
tty:[0] jobs:[0] cwd:[/opt/app] 14:50 [root@a]$ iptables -L -n Chain INPUT (policy ACCEPT) target prot opt source destination DROP all -- 10.103.55.165 0.0.0.0/0 Chain FORWARD (policy ACCEPT) target prot opt source destination Chain OUTPUT (policy ACCEPT) target prot opt source destination
15:08 [root@a]$ iptables -h
iptables v1.3.5
Usage: iptables -[AD] chain rule-specification [options]
iptables -[RI] chain rulenum rule-specification [options]
iptables -D chain rulenum [options]
iptables -[LFZ] [chain] [options]
iptables -[NX] chain
iptables -E old-chain-name new-chain-name
iptables -P chain target [options]
iptables -h (print this help information)
Commands:
Either long or short options are allowed.
--append -A chain Append to chain
--delete -D chain Delete matching rule from chain
--delete -D chain rulenum
Delete rule rulenum (1 = first) from chain
--insert -I chain [rulenum]
Insert in chain as rulenum (default 1=first)
--replace -R chain rulenum
Replace rule rulenum (1 = first) in chain
--list -L [chain] List the rules in a chain or all chains
--flush -F [chain] Delete all rules in chain or all chains
--zero -Z [chain] Zero counters in chain or all chains
--new -N chain Create a new user-defined chain
--delete-chain
-X [chain] Delete a user-defined chain
--policy -P chain target
Change policy on chain to target
--rename-chain
-E old-chain new-chain
Change chain name, (moving any references)
Options:
--proto -p [!] proto protocol: by number or name, eg. `tcp'
--source -s [!] address[/mask]
source specification
--destination -d [!] address[/mask]
destination specification
--in-interface -i [!] input name[+]
network interface name ([+] for wildcard)
--jump -j target
target for rule (may load target extension)
--goto -g chain
jump to chain with no return
--match -m match
extended match (may load extension)
--numeric -n numeric output of addresses and ports
--out-interface -o [!] output name[+]
network interface name ([+] for wildcard)
--table -t table table to manipulate (default: `filter')
--verbose -v verbose mode
--line-numbers print line numbers when listing
--exact -x expand numbers (display exact values)
[!] --fragment -f match second or further fragments only
--modprobe=<command> try to insert modules using this command
--set-counters PKTS BYTES set the counter during insert/append
[!] --version -V print package version.
接下来新建一条
15:10 [root@a]$ iptables -A INPUT -s 16.16.136.66 -j DROP
由于写的是自己的ip地址,回车后已不能继续在服务器上继续操作...只能找同学帮忙删了服务器上的配置
查看一下
15:12 [root@a]$ iptables -L -n Chain INPUT (policy ACCEPT) target prot opt source destination DROP all -- 10.166.16.66 0.0.0.0/0 DROP all -- 16.16.136.66 0.0.0.0/0 Chain FORWARD (policy ACCEPT) target prot opt source destination Chain OUTPUT (policy ACCEPT) target prot opt source destination
15:12 [root@a]$ iptables -D INPUT 2