RobIncMBAperma
Technical User
I have a question pertaining to WinXP's implementation of PING--and probably other MS flavours as well.
I, as I'm sure many other home users do, have a system that hides behind a (insert brand name) consumer home router/firewall. WinXP is set up, again, as I'm sure many other cable modem users do, to obtain its Private IP, default gateway, and DNS server information automagically via DHCP through the router.
Having been active online since the 80s, I thought I understood most of the nuances of the little tools we have come to take for granted--like PING... So here's where I kind of am not sure if I should feel dumb or rightly puzzled...
PING localhost behaves as it should. No surprise there.
For some strange reason (I can't remember), this morning I typed "PING ?" and was quite surprised when it returned my EXTERNAL IP. Forgive me if my lack of sleep has made me overlook something obvious, but as far as I know, my happy, oblivious little WinXP machine behind the router should know nothing of the actual external IP address... It is told what private IP address to use, what gateway to the Internet to use--and even uses the router as a DNS server--but should see my cable modem's actual IP address as if it were any other IP address on the Internet...
Is there some magical switch to PING that I've overlooked that causes my machine to fetch the cable modem's IP address, router and firewall notwithstanding, and somehow knows to associate itself with this IP address? It kind of scares me to think about it...
I, as I'm sure many other home users do, have a system that hides behind a (insert brand name) consumer home router/firewall. WinXP is set up, again, as I'm sure many other cable modem users do, to obtain its Private IP, default gateway, and DNS server information automagically via DHCP through the router.
Having been active online since the 80s, I thought I understood most of the nuances of the little tools we have come to take for granted--like PING... So here's where I kind of am not sure if I should feel dumb or rightly puzzled...
PING localhost behaves as it should. No surprise there.
For some strange reason (I can't remember), this morning I typed "PING ?" and was quite surprised when it returned my EXTERNAL IP. Forgive me if my lack of sleep has made me overlook something obvious, but as far as I know, my happy, oblivious little WinXP machine behind the router should know nothing of the actual external IP address... It is told what private IP address to use, what gateway to the Internet to use--and even uses the router as a DNS server--but should see my cable modem's actual IP address as if it were any other IP address on the Internet...
Is there some magical switch to PING that I've overlooked that causes my machine to fetch the cable modem's IP address, router and firewall notwithstanding, and somehow knows to associate itself with this IP address? It kind of scares me to think about it...