How many ips can i ban in iptables?


i read in config server firewall something like that many ips blocked in iptables a flood of ips can cause dos by iptables, meaning some overload or something. im not sure if its true. But i want to ask how i can see how much ips blocked in iptables is too much? where can i check it. Is there any hard limit or how to determine acceptable number keeping in ming that i have 6x2.2Ghz cpu and 8gb ram + basic 7k rpm disk?

Something tells me IPTABLES can check IP’s faster than connections can be made (in other words I’d be pretty sure the front side bus and CPU would be quicker than the network adapter) … I’d expect it to be doing a lot of waiting around.

This just doesn’t “ring true” to me.

Plus, I’d expect it to be all over the web if it were true.