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Send a DNS query
specifying one of the
criteria specific DNS
host names
Does the DNS query
response contain at
least one DC?
Quit indicating
the reason
No
Among all DCs returned in the
DNS response is there at least
one non-pinged one?
Yes
No
Among all DCs returned by the DNS server, that has not
been pinged yet, choose one DC based on weighted
random order. Ping it. Wait for 0.1 sec and listen for
responses from this and previously pinged DCs.
Did you receive a
DC's response?
No
Does it match
client's
requirements?
Yes
No
Cache the the
result and
return it to
client
Yes
Finish
Finish
Yes
Discovering Site specific DCs
When a locator searches for a DC, it attempts to find one in the same site where
the client is unless specified otherwise. If at the beginning of the search the locator
is not aware of the client’s site, it will query a DNS server for the records of the DCs
in the specified domain. Then it contacts discovered DCs and finds the site to which
the client belongs. If the discovered DC is not in the same site the locator will repeat
DNS query specifying the client’s site.
Windows 2000 White Paper
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