tty:[0] jobs:[0] cwd:[/opt/app/]14:50 [root@a]$ iptables -L -nChain 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 -hiptables v1.3.5Usage: 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.

15:10 [root@a]$ iptables -A INPUT -s 16.16.136.66 -j DROP

15:12 [root@a]$ iptables -L -nChain INPUT (policy ACCEPT)target     prot opt source               destination         DROP       all  --  16.16.56.166        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