Pinging non existing machines and getting response
 

Hi, recently I have noticed an odd problem with my LAN.

I can ping any name, even machines that don't exist. eg "ping notexist".
This gives me a reply:

Pinging notexist.cable.virginmedia.net [81.200.64.50] with 32 bytes of data:

Reply from 81.200.64.50: bytes=32 time=41ms TTL=108
etc

I would expect to get an "unknown host" when I ping an unknown machine, I'm sure that is what used to happen. I don't know why cable.virginmedia.net is getting involved.

I'm not sure if this is an ISP issue, a router or cable modem one, or some other lan issue. I'm using XP, but have windows 7 on the lan, which I was troubleshooting when I discovered this.

I suppose it is DNS related, but am not sure how to troubleshoot it.
thanks for any advice.

Re: Pinging non existing machines and getting response
 

Transparent proxy?

Re: Pinging non existing machines and getting response
 

thanks. No proxy involved that I know of. How would I know if I had a "transparent proxy"? It is happening on several machines, so cannot be caused by a proxy setting on any one machine.

Re: Pinging non existing machines and getting response
 

That IP address leads back to a company called Nominum who are providers of DNS services amongst other things.
http://www.nominum.com/

I'm not sure of the significance of this. Does the name ring any bells for you?

Re: Pinging non existing machines and getting response
 

Virgin media name servers seem to catch all non existant
domain look ups and return an ip which takes you to their
search page. You would normally get NXDOMAIN
returned from a nameserver. Try it in a web browser.

Re: Pinging non existing machines and getting response
 

ok, that is making sense now.

I have been confused in the past when I type a URL wrong and virgin "helpfully" send me to a page suggesting other alternatives.

I always wondered how that worked without me having installed any software... duh.

Typing that address in the browser as suggested goes to:

http://advancedsearch.virginmedia.com/subscribers

Now I see there is an option to turn it off...

Having done that (by clicking through a series of pages), ping now works properly again.

thanks to all!

Now I can see what machines really are there without these confusing phantom responses.

Re: Pinging non existing machines and getting response
 

if you ckick on Customer Spotlight
it leads to http://www.nominum.com/pdf/case-stud...dy_2_19_09.pdf

Re: Pinging non existing machines and getting response
 

Thanks for that. :)