Round Robin doesn't work / subnet prioritization

[Dreamzwalker]

Hi @all,
i've queried the net for hours now and have no idea how to solve my issue.

I've a Server A (W2000 SP4 all patches) that should resolve a hostname to Server B or C with round robin.
Server A and B are in the same subnet and server C is not.

Server A ALWAYS resolve Server B and never Server C.

Why? Is seems to be because M$ "subnet prioritization". The server always chooses the DNS entry tht is closest zu him.

You can disable this feature. M$ says:

Although subnet prioritization does reduce network traffic across subnets, in some cases you might prefer to have the round robin feature work as described in RFC 1794. If so, you can disable the subnet prioritization feature on your clients by adding the PrioritizeRecordData registry entry with a value of 0 (REG_DWORD) to the following registry subkey:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\DnsCache\Parameters

http://www.microsoft.com/technet/prodtechnol/windows2000serv/reskit/cnet/cncf_imp_tibv.mspx?mfr=true

Very nice but it doesn't work.
I've set up an own DNS server (instead of the DNS server of the provider) to enable "Round Robin" and disable "Enable netmask ordering" that that doesn't help, too.

Any Idea or a simple tool that can help me?

Thanks DZ

 

[ShackDaddy]

Have you narrowed down whether it is the DNS server handing the records to you in a specific order or your client choosing which of the records to use?

Have you noticed whether the DNS server reverses the order of the RR'd records on successive queries from different clients? An NSLOOKUP query won't be affected by local prioritization settings, so you should be able to analyse server behavior using NSLOOKUP and decide whether it's the server handing them out in a particular order or whether the client is the one controlling which is used.

ShackDaddy

 

[Dreamzwalker]

Hi ShackDaddy,
thanks for you reply. I've already checked it. It seems to be the client.
The nslookup says i.e.

Non-authoritative answer:
Name: Name.of-Server.com
Addresses: 1.1.1.1, 2.2.2.2

When I ping the host it is always resolved with 2.2.2.2.
(Because pinging host is also in subnet 2.2.2.0)

It is a miracle to me.
DZ

 

[ShackDaddy]

Did you actually get the hotfix that goes with the reg-entry on SP4?

http://support.microsoft.com/kb/q196500/

 

[Dreamzwalker]

Hi Shackdaddy,
finally find my mistake.
The regkey path is
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\PrioritizeRecordData
but I changed:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\DNSCACHE\Parameters\PrioritizeRecordData

http://support.microsoft.com/kb/196500/en-us

Thnaks DZ