iptables 可以支持多少条规则？

Question

最近有人问我这个问题，我没有回答。我知道这是一个开放式问题，但是您可以在表/链中安装的规则数量有限制吗？如果是这样，我怎样才能找到它？我想它会因机器而异。

Answer 1

报价自 Jan Engelhardt

The theoretical upper limit of maximum number of rules for a 32-bit
environment would be somewhere around 38 million, but you could also
construct a rule that is so crowded with matches that even it won't
fit, so the lower limit of max rules is 0.

http://www.spinics.net/lists/netfilter/msg51895.html

Answer 2

根据linuxquestions.org，在 32 位机器上，IPTables 将支持大约 25,000 条规则。超出这个范围，特别是从 27,000 开始，事情开始变得不稳定。