Re: Types of firewall...

From: bensmyth (noreply_at_test.com)
Date: 03/29/05 

Date: Tue, 29 Mar 2005 14:18:03 +0100

> > 1. Static packet filter
> > 1.1 Dynamic packet filter
> >
> > 2. Proxy server
> > 2.1 Circuit level proxy
> > 2.2 Application level proxy
> >
> > 3. Stateful Multilayer inspection
> >
> > Is this a correct, complete list?? Or am I missing something??
>
> I'm afraid there will never be a "correct, complete list", there
> are too much going on, too many firewall architectures that won't
> fit a single type definition (and maybe not even multiple!). Not
> that it isn't worth trying, though... but it might be a degree in
> itself.

How does the following sound...

static packet filter - Network Level - Filters on basis static rule-set of IP
packet header
dynamic packet filter - Network/Transport levels - as above +dynamic rule-set
which maintains list of current open unprivileged ports (thus, no need to open
all unprivileged ports)

proxy - transport or application level - man-in-the middle

Stateful multilayer inspection - Network, transport and application - provides
dynamic packet filter + algorithms to recognise and process application layer
data (which are faster than application-proxy approach)

Regards,

Ben