confused by IP address

Alcatel Speedtouch 510, 1mb broadband connection (pipex).

I just switched from Demon,where I had a static IP address (shown in
the header). My PC is set NOT to get an IPO address automatically.

Here's my confusion. My router says my IP address is 81.179.64.2, but
my PC's TCP/IP properties show it as 192.168.254.2

Everuthing works ie connection to the internet, connection to my
laptop over both wired and wireless.

If I set my PC's address to the static one 81.179 etc, nothing works.

I'd really appreciate an explanation as to what's going on here - why
the pc has a different ip address to that used by the router?

I'm sure it's a stupid question, but I'm trying to learn.....

On Wed, 03 May 2006 16:03:08 +0100, Pete wrote:

> Alcatel Speedtouch 510, 1mb broadband connection (pipex).
>
> I just switched from Demon,where I had a static IP address (shown in
> the header). My PC is set NOT to get an IPO address automatically.
>
> Here's my confusion. My router says my IP address is 81.179.64.2, but
> my PC's TCP/IP properties show it as 192.168.254.2
>
> Everuthing works ie connection to the internet, connection to my
> laptop over both wired and wireless.
>
> If I set my PC's address to the static one 81.179 etc, nothing works.
>
> I'd really appreciate an explanation as to what's going on here - why
> the pc has a different ip address to that used by the router?
>
> I'm sure it's a stupid question, but I'm trying to learn.....

Network Address Translation (NAT). Do a Google search or read your router's
manual.

Pete wrote:

<snip>


> Here's my confusion. My router says my IP address is 81.179.64.2, but
> my PC's TCP/IP properties show it as 192.168.254.2
>
> Everuthing works ie connection to the internet, connection to my
> laptop over both wired and wireless.
>
> If I set my PC's address to the static one 81.179 etc, nothing works.
>
> I'd really appreciate an explanation as to what's going on here - why
> the pc has a different ip address to that used by the router?
>
> I'm sure it's a stupid question, but I'm trying to learn.....

It's called NATting (NAT=Network Address Translation)

Your PC really does have an IP of 192.168.254.2.

The alcatel has two addresses - 1 for the internet (which is
81.179.64.2) and one to talk to the PC with (which must be on the
192.168.254.0/24 network, probably 192.168.254.1)

The pC is not directly connected to the internet - it has the alcatel
set up as it's default gateway (probab;y at 192.168.254.1) and the
aclatel translates requests coming from the PC at 192.168.254.2 to the
internet address of 81.179.64.2

On Wed, 03 May 2006 14:38:55 -0400, snertking
<(E-Mail Removed)> wrote:

>Pete wrote:
>
><snip>
>
>
>> Here's my confusion. My router says my IP address is 81.179.64.2, but
>> my PC's TCP/IP properties show it as 192.168.254.2
>>
>> Everuthing works ie connection to the internet, connection to my
>> laptop over both wired and wireless.
>>
>> If I set my PC's address to the static one 81.179 etc, nothing works.
>>
>> I'd really appreciate an explanation as to what's going on here - why
>> the pc has a different ip address to that used by the router?
>>
>> I'm sure it's a stupid question, but I'm trying to learn.....
>
>It's called NATting (NAT=Network Address Translation)
>
>Your PC really does have an IP of 192.168.254.2.
>
>The alcatel has two addresses - 1 for the internet (which is
>81.179.64.2) and one to talk to the PC with (which must be on the
>192.168.254.0/24 network, probably 192.168.254.1)
>
>The pC is not directly connected to the internet - it has the alcatel
>set up as it's default gateway (probab;y at 192.168.254.1) and the
>aclatel translates requests coming from the PC at 192.168.254.2 to the
>internet address of 81.179.64.2

Thanks for that. Simple when you know!

So if I read it right - if I use certain p2p programs, I should open
ports using the router's ip address, not the pc's one?

<Pete> wrote in message
news:(E-Mail Removed)
> On Wed, 03 May 2006 14:38:55 -0400, snertking
> <(E-Mail Removed)> wrote:
>
> > Pete wrote:
> >
> > <snip>
> >
> >
> > > Here's my confusion. My router says my IP address is
> > > 81.179.64.2, but my PC's TCP/IP properties show it as
> > > 192.168.254.2
> > >
> > > Everuthing works ie connection to the internet, connection
> > > to my
> > > laptop over both wired and wireless.
> > >
> > > If I set my PC's address to the static one 81.179 etc,
> > > nothing
> > > works.
> > >
> > > I'd really appreciate an explanation as to what's going on
> > > here
> > > - why the pc has a different ip address to that used by the
> > > router?
> > >
> > > I'm sure it's a stupid question, but I'm trying to
> > > learn.....
> >
> > It's called NATting (NAT=Network Address Translation)
> >
> > Your PC really does have an IP of 192.168.254.2.
> >
> > The alcatel has two addresses - 1 for the internet (which is
> > 81.179.64.2) and one to talk to the PC with (which must be on
> > the
> > 192.168.254.0/24 network, probably 192.168.254.1)
> >
> > The pC is not directly connected to the internet - it has the
> > alcatel set up as it's default gateway (probab;y at
> > 192.168.254.1) and the aclatel translates requests coming
> > from
> > the PC at 192.168.254.2 to the internet address of
> > 81.179.64.2
>
> Thanks for that. Simple when you know!
>
> So if I read it right - if I use certain p2p programs, I should
> open
> ports using the router's ip address, not the pc's one?

Forward the ports in your router if needed.

--


Travis in Shoreline Washington