Re: Name Lookup latency when resolving Internet names

Tech-Archive recommends: Speed Up your PC by fixing your registry

From: Vince C. (none_at_hotmail.com)
Date: 11/01/04 

Date: Mon, 1 Nov 2004 22:34:01 +0100

"Roland Hall" <nobody@nowhere> a écrit dans le message de news:
ul5utX%23vEHA.200@TK2MSFTNGP11.phx.gbl...
[...]
> : So the DNS latencies I'm seeing are *not* due to having a second IP on my
> : NIC, are they?
>
> I have no idea. Let's look at some other questions:
> 1. Why have you not gone back to a single IP on a single NIC to test?
> 2. Why is this being done in production?

1. Because I did already long before I posted. It didn't change anything. And
since DNS latencies occurred before - yes I repeat again - I put a second IP to
the LAN NIC... Ok, I've just once again, changed my wireless IP to one in my LAN
subnet, removed the second IP on my LAN NIC, rebooted (just in case) and...
nothing has changed. You won't tell me I didn't want to please you ;-).

Ethernet carte Réseau local :

        Connection specific DNS : mydomain.local
        Description . . . . . . . . . . . : Carte Realtek RTL8139(A) PCI Fast
Ethernet #2
        Physical address. . . . . . . . . : 00-50-BF-7B-C5-BD
        DHCP enabled . . . . . . . . . . . : No
        IP Address . . . . . . . . . . . . : 10.10.1.1
        Subnet mask . . . . . . : 255.255.255.0
        Default gateway . . . . . . :
        DNS servers. . . . . . . . . . . : 10.10.1.1
        NetBIOS over Tcpip . . . . . . . . : Disabled

2. Oh, production, production... it's a big word. It's just a test server not a
production server. I set it up for training purposes mainly.

> To MSFT, a private LAN is separate from a public LAN. Even before active
> directory, most of us knew DNS on a private LAN should be separate from a
> public LAN. They don't need to know about each other. Your clients get
> their DNS from the local DNS server. If they request a public address, the
> DNS can, either through root hosts or (a) forwarder(s), forward the request
> to be resolved for the public address. It will then cache the response so
> subsequent queries, within the ttl for the cached entry, will not have to be
> forwarded.
>
> Your local DNS name should be dotted. ex. domain.local No servers or
> workstations should have in their network settings looking at a public DNS
> server. I believe with ISA, this does not apply to the public NIC, just the
> private one.

My - test - LAN is a private one. I have installed W2K server with Active
Directory, native mode as I have no WinNT workstation. Since AD requires DNS,
there is no other choice. And I wanted to try Active Directory. And my domain,
mydomain.local - which is not the real one but... you know - is dotted. Just
like W2K adv. server Setup Wizard told me it had to be when I installed the
server.

> Why is this included on the LAN NIC settings?
>
> Liste de recherche de suffixe DNS : mydomain.local
> teledisnet.be

teledisnet.be is my ISP's DNS, on the public NIC (DHCP client). mydomain.local
is my local domain.

> Also, are you running in native mode?

Yes.

But what if we got back to my problem? On the server itself I can type "nslookup
www.microsoft.com" three times until I get a non-timed-out response. It's just
as if DNS results were *not* cached. OTOH there is no "cached results" in the
DNS tree on the server DNS, like I see on my company's domain controller. Note
the latter doesn't run AD natively but mixed. Does it help?

Vince C.

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