Firewalls vs Proxy Server

[Gothe]

Can this group tell me the difference between a firewall and a proxy server?
Are there differences? Advantages or disadvantages one or the other. This
would greatly help me with a school project. Post to this thread or e-mail.

Thank you, JT

[Frederick M Avolio]

Gothe wrote:
>
> Can this group tell me the difference between a firewall and a proxy server?

Well of course. This is the Internet, afterall. Your job is to see if
you can discern a *correct* answer! :-)

> Are there differences? Advantages or disadvantages one or the other. This
> would greatly help me with a school project. Post to this thread or e-mail.

A proxy server may not be a firewall. A firewall may be
created using application level proxies, circuit level proxies,
packet filters, or a combination.

A proxy acts on behalf of another, in another's place. In the
case of proxy software -- security or otherwise -- it looks
to the server like a client, and to the client like a server.

On generic proxy servers, this is basically all it does, though
typically it also caches information. MS Proxy Server, for example,
was written to do this, with the benefit of speeding up web access
because of the Proxy Server cache.

Proxy-based firewalls utilize proxy servers, but with different
intent.
They do this to 1) separate one network from another (something that
filtering firewalls do not do), 2) log information, and 3) examine the
data attempting to cross the gap and applying security policy rules
against it.

Proxies used for firewalls -- security proxies -- were invented by
Marcus Ranum in 1990 or 1991.

Fred
--
Avolio Consulting
16228 Frederick Road, PO Box 609, Lisbon, MD 21765
410-309-6910 (voice) 410-309-6911 (fax)
http://www.avolio.com/

[Craig Wiesner]

Here are a few URLs to help with the homework.

http://www.interhack.net/pubs/fwfaq/
http://www.3com.com/nsc/500619s.html

Craig Wiesner - WK Multimedia Network Training
http://www.wkmn.com Visit our Faster LAN and Security Web Site

Gothe wrote:

> Can this group tell me the difference between a firewall and a proxy server?

> Are there differences? Advantages or disadvantages one or the other. This
> would greatly help me with a school project. Post to this thread or e-mail.
>

> Thank you, JT