Skip site navigation (1)Skip section navigation (2)
Date:      Thu, 27 Apr 2000 09:03:28 GMT
From:      Salvo Bartolotta <bartequi@neomedia.it>
To:        Yamin Prabudy <min@starindo.net>, freebsd-questions@FreeBSD.ORG
Subject:   Re: DDos
Message-ID:  <20000427.9032800@bartequi.ottodomain.org>
References:  <39081EA0.51160471@starindo.net>

next in thread | previous in thread | raw e-mail | index | archive | help
>>>>>>>>>>>>>>>>>> Original Message <<<<<<<<<<<<<<<<<<

On 4/27/00, 12:04:00 PM, Yamin Prabudy <min@starindo.net> wrote
regarding DDos:


> Denial of Service Attacks
> Can anyone explain what is this
> and how can i defense my self with this kind of attacks
> I'd notice that a couple of ISP in INdonesia had been a victim

> TIA

> -Yamin-


Dear Yamin Prabudy,

DDoS stands for Distributed Denial of Service [attack]. That is, [a
great] many computers *simultaneously* attack one site, throwing data
at it at, say, ~1 Gbit/sec rate. The goal of this type of attack is to
prevent the victim from providing any services.

You might want to do a little search on the web for this: some
"famous" DDoS attacks were performed in February, and you should find
plenty of information about them.

As to defence strategies, to begin with, you might want to have a look
at the following:

1) a few options for your kernel: e.g. ICMP_BANDLIM, TCP_RESTRICT_RST,
IPFIREWALL, etc.
2) Packet filtering ("firewall") techniques, eg. ipfw(8), ipf(1,5,4),
etc.

You might want to read (wait for it) the handbook for an introduction
to these complex problems as well as ... the freebsddiary. And you
might want to have a look at a few good books on firewalls.

This topic has been discussed again and again on -questions, and you
might want to search the mailing list archives, too.

N.B. while a (single) DoS is fairly easy to deal with, a DDoS is quite
another matter.

Best regards,
Salvo





To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-questions" in the body of the message




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20000427.9032800>