Re: Private IP address with yahoo messenger

["Colin Copley" <colin.75 () btinternet com>]

> On Tuesday 22 May 2007 11:21 pm, Alcides wrote:
> While having a chat session with somebody in yahoo messenger, how is
> it possible to obtain his/her Private IP address if that person is
> behind a Router and/or a Firewall (NATed)?
>
> Moreover,
> Is there any way that he/she can hide successfully (behind the NAT or
> something else)so that NO internal IP address is revealed?

Yes.
The internal IP addresss should go no further than a table in the NAT router
so the router remembers where to send the reply.
It is replaced after this point by the public IP address of the router.

Perhaps Yahoo Messenger could wrap up the internal IP address and use it to
create some kind of transaction ID, which it sends with the message but
although I'm not familiar with the software, I'm pretty sure many have
checked and cant imagine something like that going unnoticed.  However
Ethrereal/Wireshark will capture the packets for you to inspect and make
comparisons.  Remember you _will_ find your local ip address in the source
field of the ip packets, but this will be swapped by the NAT device.

Presumably you can send http links in Yahoo chat?

Your best bet might be a java, javascript, or activeX program to grab the
internal IP address and relay it.

Kind regards
Colin