Blocking very many (tens of thousands) ip addresses in ipfw

[Pieter de Goeje]

On Wednesday 14 January 2009 18:13:06 Steve Bertrand wrote:
> Pieter de Goeje wrote:
> > On Wednesday 14 January 2009 17:23:25 Artem Kuchin wrote:
> >> I need to block around 150000 ip addreses from acccess the server at all
> >> at any port.  The addesses are random, they are not nets.
> >> These are the spammer i want to block for 24 hours.
> >> The list is dynamically generated and regenerated every hour or so.
> >> What is the most efficient way to do it?
> >> At first i thought doing ipfw rules using 5 ips per rule, that would
> >> result in 30000 rules! This will be too slow!
> >> I need to something really quick and smart. Like matching the first
> >> number from ip (195 from 192.1.2.3),
> >> if it does not match - skip, if it does - compare the next one
> >> and so on.
> >
> > Quoting ipfw(8):
> > LOOKUP TABLES
> >      Lookup tables are useful to handle large sparse address sets,
> > typically from a hundred to several thousands of entries.  There may be
> > up to 128 different lookup tables, numbered 0 to 127.
> >
> > net.inet.ip.fw.dyn_buckets should probably also be increased to
> > efficiently handle 150k IPs.
>
> Please correct me if I'm wrong, but if the OP is going to drop all
> traffic immediately from the 150k IPs, then dyn_buckets shouldn't come
> into play, as there is no dynamic rule generated.
>
> Steve

Ah nevermind then, I misread the manpage. I thought it also applied to normal 
tables.

-- 
Pieter de Goeje