Getting public IP address of NAT firewall

[Rasjid Wilcox]

On Thu, 7 Feb 2002 11:28 pm, Rasjid Wilcox wrote:
> Suppose that I have a hardware fireall that does NAT and it is given a
> dynamic IP address by the ISP.  Is there any way for a user of a
> workstation behind the firewall to find out the public IP address of the
> firewall without logging into the firewall?
>
> What I'm thinking is, is there any information kept in the TCP/IP headers
> that would allow me to do this, or is that all lost during the NAT/IP
> masquarade process?
>
> Rasjid.

The following seems to do what I want.

$ ping -c 1 -R www.webone.com.au | grep -C1 "RR:" | tail -n1
        dialup-host.webone.com.au (123.231.123.231)

Thanks to all who replied.

Rasjid.

PS.  I'm sure there is a better way of saying 'the line after the one where 
"RR:" appears', but it works.