Firewall basics

Firewall basics

am 11.01.2008 02:43:41 von securitylearner

I would like to know how a software firewall application receives and
can check all the packet intended for any port?

I mean Is there any special port on which all incoming data is
forwarded first? or Firewalls use something like port 0 to receive all
data? In anyway please explain in detail which port is used?

Re: Firewall basics

am 11.01.2008 10:00:08 von unknown

Post removed (X-No-Archive: yes)

Re: Firewall basics

am 11.01.2008 13:03:27 von MR. Arnold

wrote in message
news:bed44781-c6a4-417c-8b5c-e8809aa9ac25@e10g2000prf.google groups.com...
>I would like to know how a software firewall application receives and
> can check all the packet intended for any port?
>
> I mean Is there any special port on which all incoming data is
> forwarded first? or Firewalls use something like port 0 to receive all
> data? In anyway please explain in detail which port is used?

What you have running on your computer is not a firewall. It's a machine
level packet filter. A FW will have at least two interfaces or NIC(s) if
it's a software FW running on a gateway computer. A FW sits at the junction
point between two networks. A FW protects from a network usually the
Internet, and it protects a network (computers on a LAN).

http://www.vicomsoft.com/knowledge/reference/firewalls1.html #5

This too may help you in understanding FW(s) and what is a FW and what is
not a FW.

http://www.more.net/technical/netserv/tcpip/firewalls/