IPTABLES Rate Limit
 

Well, I was having Ddos attack from multiple IP's on probably 3 of my machines one of which is CentOS and two are Debian. I had added rate-limiting to my rules to protect it but I just observed its not working and server is making 1mb/s output easily.


All systems were on OpenVZ running 2.6.18 kernel.

On all systems iptables version was 1.4.5+. I downgraded to 1.3.5 with RPM on CentOS machine and iptables started working easily. Now I need an answer to why they didn't work on later versions? Is it something related to version compatibility with the kernel?

Now I can't find any deb files for Debian so I want someone to help me out with the file on Debian so that I can dpkg -i the package and try it out on Debian too, please help.

Thanks!

Well, I don't have an answer for you, but I did have a look through the release notes, and I didn't see anything even vaguely like "completely changed the syntax for rate limiting to cure ...". Now, maybe there is something there, but it didn't jump out...maybe beyond 1.4.5, maybe it was there but wasn't all that obvious, but I didn't really find anything, not that this was such a big surprise.

If something doesn't come up here, you may be better trying the mailing list at netfilter, as this could be quite a specialised question.

Yes I mailed them about it and also submitted that in BugZilla.

Could anyone provide Debian binary package for iptables 1.3.5 so I can downgrade there too?

Searched a lot but cant find it.

Update :

Updating Debian to Debian 6 and iptables 1.4.8, easily blocked the attack.

Why would Debian 5 running same version wont block it?

Or is it that the attack is already blocked but iftop is not showing it?

Not a bug in iptables.

More of something mysterious:

http://www.linuxquestions.org/questi...k-ddos-931931/