nanog mailing list archives

Re: ACLs vs. full firewalls


From: Ravi Pina <ravi () cow org>
Date: Wed, 15 Apr 2009 12:45:09 -0400

On Wed, Apr 08, 2009 at 08:32:02AM +1000, Karl Auer wrote:
On Wed, 2009-04-08 at 07:04 +0930, Mark Smith wrote:
It seems there is a trend towards moving host protection on to the
hosts themselves, onto or closer to the resource or entity being
protected. It's basically following the cliche, "If you want something
to be done properly, you need to do it yourself."

And IPv6 tends to push security back onto hosts, too.

If you move to the host-based firewalling model, plain packet
filtering ACLs at the perimeter would be quite an adequate form of a
first level of defence, while also avoiding the performance overhead
of (or resources required to perform) stateful tracking of large
amounts of traffic. 

And a combination of the two - if you *are* performing more complex
checks deeper inside the network, packet filtering can reduce the load
that actually reaches those inner check points.

Which would address my concern of just passing along the [D]DOS to the
host.  Mitigating attacks at the border and letting the hosts allow
what they specifically need is a good model.

I'd be interested to hear why people use firewalls. I've never felt the
need, myself - am I living in a fool's paradise?

By your email I'll assume you've never had to deal with HIPPA[1] or
SOx[2].  That aside I see a value in using a stateful FW that does
packet inspection to validate the type of traffic over a certain port
should really be there.

-r


[1] http://en.wikipedia.org/wiki/HIPPA
[2] http://en.wikipedia.org/wiki/Sarbanes-Oxley_Act




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