DNS (Domain Name Service) translates symbolic addresses, to
numeric addresses. When you use a browser, and type in
www.aol.com,
that has to be converted to a number. DNS does that.
To test DNS, open a Command Prompt window (DOS window). Try
nslookup
www.aol.com
Mine returns:
Server: (Address of the DNS server provided by my ISP)
Address: My local IP address (on the LAN side of my router, not my
WAN address)
Non-authoritative answer:
Name:
www.aol.com.websys.akadns.net
Addresses: 205.188.102.114, 205.188.101.114, 205.188.100.114
Aliases:
www.aol.com
If I enter "
http://205.188.102.114" without the double quotes, and
hit return in my browser, I'll see the AOL home page. In this second
case, since I provided the number, there is no DNS step to do.
Try
http://205.188.102.114 and see if you get AOL. If so, then
probably there is a problem with DNS setup. (If the symbolic
www.aol.com
doesn't work, and yet the number one does, it means DNS is busted somehow.)
Note that me choosing
www.aol.com as an example, isn't very bright. Some
of the larger sites, use complicated networking setups, where they
need the symbolic info as well, to resolve properly. I got lucky in this
case, that AOL actually responded to one of those numbers. Still, give
it a try.
If you are using DHCP to talk to your ISP, then DHCP should automatically
get DNS server info from the ISP (see your Network control panel). It
could be, that the DNS server they fed you, is currently having problems,
and is not responding. If they give you two DNS servers, and the first one
is busted, sometimes the symptoms seen will be a long delay before any
symbolic address is resolved. Like every web page takes 10 seconds to
open. That is because the OS stupidly tries the busted one first,
every time.
Another DOS window command I use occasionally, is
ipconfig /renew
What that does, is renew the DHCP lease and get a new public address
for your networking setup. That seems to be needed
sometimes, to clean up my network setup.
http://www.microsoft.com/resources/.../xp/all/proddocs/en-us/ipconfig.mspx?mfr=true
There is also a page for nslookup, that doesn't help much.
http://www.microsoft.com/resources/.../xp/all/proddocs/en-us/nslookup.mspx?mfr=true
HTH,
Paul