Blocking an ISP?

[Daemon1]

I am getting flooded out by some user on skynet.be, the IPs change to often to keep blocking them. Does anyone know how to block an entire ISP from accessing my server, either via IP tables or some other way? Thanks.

[chirpy]

You need to locate their IP blocks in one of APNIC/ARIN/RIPE and then use their CIDR to drop the whole network using iptables.

[Daemon1]

So if I were to block each one of them how would it be done?

I found the IPs i need to ban on htp://www.fixedorbit.com/cgi-bin/cgirange.exe?ASN=5432. Using the first one listed as an example, how would be the correct format to ban the ip and all its ranges.

62.4.128.0 start IP
62.4.255.255 end IP

/sbin/iptables -I INPUT -s 62.4.128.0/255 -j DROP

Is that correct? Or does the format need to be different to cover that entire range

[chirpy]

Not /255, here's a nifty page explaining CIDR:
http://public.pacbell.net/dedicated/cidr.html

Other than that, your command looks good.

[easyhoster1]

/sbin/iptables -I INPUT -s 62.4.128.0/255 -j DROP

A class C would be

/sbin/iptables -I INPUT -s 62.4.128.0/24 -j DROP