Periodically my server gets hammered so hard by automated comment spam runs against my blogs that the server goes down and I have to annoy my provider to get a power cycle if I don't see it happening and start blocking IP addresses. I spend hours and hours using netstat commands (copy and paste as suggested by other people) to generate lists of IPs and count of connections. Generally I find that it is a Web Hosting company with a lax attitude to this sort of thing and try and block the entire range in IPTables. If I spend long enough my then things calm down for a while. Then the whole cycle starts up again.
What else can I do to stop spammers bringing my server to it's knees every month or so?
My IPTables block list seems huge and I have even imported massive lists all to no avail. I seem to recall that I installed things like MOD_Evasive and Shields Up way back when (can't really remember) but clearly this is no longer working.