All of lore.kernel.org
 help / color / mirror / Atom feed
From: Chris Brenton <cbrenton@chrisbrenton.org>
To: netfilter <netfilter@lists.netfilter.org>
Subject: Re: blocking by domain
Date: Sun, 13 Jun 2004 07:26:37 -0400	[thread overview]
Message-ID: <1087125996.2011.6.camel@grendel> (raw)
In-Reply-To: <1087115340.1891.2.camel@anduril.intranet.cartel-securite.net>

On Sun, 2004-06-13 at 04:29, Cedric Blancher wrote:
>
> Moreover, I
> think it would generate too much latency if you had to check DNS for
> packets at firewall level.

Not to mention the accuracy is pretty poor. Say I'm fubar.com and you
have a rule blocking traffic from my domain. I can either:

1) Not create a PTR record for my IP
2) Create a PTR calling myself www.microsoft.com or similar

Both methods will defeat a domain based filter. So blocking at an IP
level is faster and more accurate. Best bet is to just do a few whois
queries to identify the IP range for the domain and block accordingly. 

HTH,
Chris




      reply	other threads:[~2004-06-13 11:26 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-06-12 21:27 blocking by domain Spiro Azkoul
2004-06-13  8:29 ` Cedric Blancher
2004-06-13 11:26   ` Chris Brenton [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1087125996.2011.6.camel@grendel \
    --to=cbrenton@chrisbrenton.org \
    --cc=netfilter@lists.netfilter.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.