Connection-specific DNS suffix - possible problems?

[John Gray]

Suddenly when doing an IPCONFIG /ALL (as you do, occasionally) I find that instead of the usual null following the "DNS suffix search list" and "Connection-specific DSN suffix" lines I now have "cable.virginmedia.net". This has the unusual effect of giving me a completely non-192.168.m.n IP address for one PC when PINGed from the other PC, in fact an 'external' one 82.33.x.y.

Can anyone think that there could be more serious problems in what Virgin Media calls an 'advanced network error search enhancement', or some such?

I've asked for it to be turned off for me, but it would seem I have to clear a cache somewhere, probably browser...

Thanks!

[StuartR]

John,

You can get those DNS suffixes from two places:

1. The DHCP server on your network, this will probably be your ISP provided router
2. The TCP/IP setup on your local computer

It is NOT something that has come from your DNS server.

The way these are used is that if you lookup a hostname that is not fully qualified, for example
\\server\fileshare
then your computer will try each of those suffixes to try and find a match, so in your case it will try
\\server.cable.virginmedia.net\fileshare

If you don't like the searches that your ISP is doing then you could configure your computers (or your router) to use a completely different DNS server if you want. For example I have my router configured to use OpenDNS instead of my ISP's DNS servers.

[John Gray]

Thanks, Stuart - I found that "cable.virginmedia.net" had appeared in one of my router settings, so (shortened account!) I turned it off at the VM end and in the router, then rebooted the PC and the router and the cable modem, and the IP addresses have gone back to their normal 192.168.m.n format.

The matter was complicated because my homeplug WAP seemed not to be passing through DHCP from the router to laptops, and there the only thing that worked was a reboot of the homeplug WAP - swapping among assorted wireless USB devices did nothing...

[StuartR]

...(shortened account!)...

In my experience these things always turn into a long saga.

Glad you got it fixed.