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On Windows, I do ipconfig /displaydns

One record is:
 Record Name . . . . . :
 Record Type . . . . . : 5
 Time To Live  . . . . : 8
 Data Length . . . . . : 8
 Section . . . . . . . : Answer
 CNAME Record  . . . . :

I see no IP for it.

How does Windows resolve the IP for this then?

Note: there is no other entry for

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up vote 1 down vote accepted

CNames or canonical names basically let you alias one domain name to another - this makes it simpler if you have lots of domain names pointing at the same server - for example, you had seperate domain names for FTP, different domain names for vhosts and so on.In this case points at, which then points at somewhere else.

If you run tracert on, it'll look up

and you get


Tracing route to []
over a maximum of 30 hops:

Which means it simply resolves the ip address for the domain when you ask for

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So it never caches it? And has to resolve it each time? – dublintech Jun 17 '12 at 10:13
Apparently not. Bizarrely tracert-ing na4-was results in it showing up as a cname for itself... which makes no sense at all. – Journeyman Geek Jun 17 '12 at 10:17
@dublintech, sorry, why do you think cname records aren't cached? They are cached like anything else. – Zoredache Jun 17 '12 at 10:28
@Zoredache there was no corrresponding entry for the cname record in the cache, in this case. – dublintech Jun 17 '12 at 20:16

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