Re: [PCTECH] Need firewall protection,

[David Gibbs <david@xxxxxxxxxxxx>]

Dan Bale wrote:
> I am going to ask one more question relating to this.  Couldn't a router be
> fooled, "spoofed" if you will, by an "uninvited" guest on the outside
> sending something to the router so that it believes it is a result of
> something initiated on my PC?

Nope ... routers have to network interfaces ... one for the outside, one 
for the inside.  Anything coming in from the outside goes nowhere. 
Stuff from the inside is routed through to the outside interface.

> How does the router/firewall
> assure that the information it receives is coming from a source that the PC
> initiated?

MAC address ... each network interface has one.  It's unique (more or 
less).

If someone REALLY REALLY REALLY wanted to send a virus to you I guess it 
is theoretically possible for them to be a 'man in the middle' and spoof 
the remote IP & MAC address.  But I don't think it's very practical.

'course if the information is really important, it would no doubt be SSL 
encrypted ... so not only would they have to know where you are coming 
from, where you are going to, get between the two, then decrypt the SSL 
traffic.

As I've said ... there are far easier ways to steal information from 
you... like simply breaking into your house :)

david