How does IE make a request to name servers?

[Chalawal Maliwan]

Hi All,

Could anyone please enlight me on how the IE resolves names to IPs and
the inverse IP to names lookup?

I sometimes entered web address on the location bar and IE complained
that it could not find the server I entered. In contrast, when I use
"nslookup" from command prompt on Windows 2000 pro, I found that
nslookup resolves the IP correctly.

Thanks for your assistance,

Chalawal

 

[Robert Aldwinckle]

....

I sometimes entered web address on the location bar and IE complained
that it could not find the server I entered. In contrast, when I use
"nslookup" from command prompt on Windows 2000 pro, I found that
nslookup resolves the IP correctly.

Chalawal,

nslookup is doing a direct query to your DNS server.

telnet or ping -n 1 are better simulations of the lookup that IE does
because they use the DNS Client service (dnscache) or HOSTS file.

I suppose if you stopped the dnscache service and deleted your
HOSTS file you could have equivalent lookups done by IE.
However, it seems to me that nslookup is much more tolerant of delays
in the lookup than IE seems to be. For example, you may notice
that lookups done for a site's real name take less time than those done
for its alias; yet it is often the alias which is intended to be used by the
browser. That is why I often suggest that users try the real name instead
of the alias. (I don't know for sure if this is why it would work but it is
something to try.)

If you have an entry in HOSTS to act as an "accelerator" or override
for a normal lookup you may be able to see it by entering:

ipconfig /displaydns

You can pipe the output of that command into a find /i command
to search for something specific. Generally as long as your HOSTS file
doesn't have too many entries in it that should only be necessary after
you have been going to a lot of different sites within a short period.


HTH

Robert Aldwinckle
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