[Info-vax] If interested with ! For your home and professional networks

[John E. Malmberg]

On 4/22/2013 12:38 PM, Philippe.vouters at laposte.net wrote:
> http://vouters.dyndns.org/tima/Windows-Unix-OpenVMS-DNS-Comparing_DNS_search_order_between_operating_systems.html
>
> This document mainly focuses onto hostnames lookup order by three
> different operating systems.

The method that Microsoft Windows uses is actually more complex than it 
that article and can involve accessing a WINS server, a browsing 
service, and broadcasting for a response to the name.

Normally you will only see this on a company LAN with a domain 
controller, not on a personal home network.

I am not motivated to look up the exact details, but this difference 
caused many miss-diagnosis as to what was actually failing in the name 
resolution, because they were trying to diagnose a failure of one type 
of name resolution by using diagnostic tools designed for a different type.

In general Microsoft Windows programs that use the Unix socket API look 
in the hosts file first, the DNS second, and then fall back to various 
Microsoft name to IP resolutions.

For Microsoft Windows programs that use the Win32 API use the Microsoft 
name resolutions first and if that fail, fall back to using the Unix 
methods.  The Microsoft name resolution order can be controlled by 
system administrator, so may be different for different sites.

This is documented somewhere in a Microsoft networking configuration guide.

Most of the problems with the Microsoft name resolutions also were 
traced down to a misconfiguration caused by someone who did not read 
that guide.  Many of the errors would result in a configuration that 
would appear to work for a period of time and then shut down resolving 
the incorrectly configured name.

Currently I am having to periodically restart the Microsoft DNSClient 
service as it randomly stops talking to the local VMS DNS Server.

Regards,
-John
wb8tyw at qsl.network
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