Determine nearest host based on AD site info

If multiple hosts are defined with the same name, the Microsoft DNS server
has the ability to prioritize a host if it's within the same subnet as a
client (netmask ordering).
This method will most likely not be able to prioritize the right host,
unless there is a host in the exact same subnet as the client.

Would it be possible to make the DNS server prioritize the nearest host
based on AD site information?
I could use a kind of GEO location functionality, just internally in our
organisation. If the DNS service used AD site info, that should be possible.
I hoped this would be in 2008, but I can't find any such thing. Is it
possible some how?
If not, it's a feature request.
I know it would require a little more processing, but it could be an
administration option to turn it on. Like netmask ordering can be disabled.

Anyone know a thirdparty product that can do this?

"Jan Nielsen" <> wrote in message news:7DE92A62-58C4-4652-A7BF-...
> If multiple hosts are defined with the same name, the Microsoft DNS server
> has the ability to prioritize a host if it's within the same subnet as a
> client (netmask ordering).
> This method will most likely not be able to prioritize the right host,
> unless there is a host in the exact same subnet as the client.
>
> Would it be possible to make the DNS server prioritize the nearest host
> based on AD site information?
> I could use a kind of GEO location functionality, just internally in our
> organisation. If the DNS service used AD site info, that should be possible.
> I hoped this would be in 2008, but I can't find any such thing. Is it
> possible some how?
> If not, it's a feature request.
> I know it would require a little more processing, but it could be an
> administration option to turn it on. Like netmask ordering can be disabled.
>
> Anyone know a thirdparty product that can do this?


I don't know about third party tools, but what I can say is AD members are all Site aware. If there are multiple IPs for a host, and you have your AD Sites properly setup with their appropriate IP subnet objects correctly associated with the Site name, the querying client will choose a record based on Site. If there are multiple records in a Site, then Netmask Priortization will kick in for the client to choose an IP closest to its subnet, and if there are multiples, Round Robin kicks in.

This is evident with the logon process. Same goes with any AD based query, such as for a DFS. However, if it is not an AD based client-side extension running, such as for a non-AD resource lookup, it won't use Sites, rather it will use Netmask Priortization then Round Robin.


--
Ace

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Ace Fekay, MVP, MCT, MCITP EA, MCTS Windows 2008 & Exchange 2007, MCSE & MCSA 2003/2000, MCSA Messaging 2003
Microsoft Certified Trainer
Microsoft MVP - Directory Services

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