定义规则链时需要指定链要加入的表，默认加入Filter表
--append -A chain Append to chain
--check -C chain Check for the existence of a rule
--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 [rulenum]]
List the rules in a chain or all chains
--list-rules -S [chain [rulenum]]
Print the rules in a chain or all chains
--flush -F [chain] Delete all rules in chain or all chains
--zero -Z [chain [rulenum]]
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)
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iptables -t filter -N jychain
iptables -A jychain -s xxxxxxx -DROP
iptables -A jychain -m comment --comment 'dddd' -j RETURN---(返回调用主链的下一条规则)
-j RETURN 用于自定义规则链的返回主调用链，继续执行后续的匹配
//调用jychain
iptables -t filter -s xxxxx -j jychain