update different subnet in different zone
dhcp at thehobsons.co.uk
Fri Jun 2 09:02:31 UTC 2006
kalyanasundaram S wrote:
>yah well thanks,
> that works fine.
> I was confusing that while allocating the address how the dhcp
>server updates the corresponding zone.
>So just a clarrification
> if server allocates IP from one subnet it looks for
>"ddns-domainname" and update the corresponding zone
> if not found go to higher level (or global) and again look for
> If none found no update will be made?..
>am i correct?
>where all i can have this ddns-domainname option (inside =>
>subnet,pool,group,sharednetwork,host) in all these places are
>possible to have ddns-domainname option?
Recommended reading : "The DHCP Handbook" by Ralph Droms and Ted
Lemon, Macmillan Technical Publishing, ISBN 1-57870-137-6.
All this (and much more) is well explained.
But in short, and omitting a few details for clarity, all options
follow a scoping heirarchy. You can define an option in several
The server evaluates any declarations from global downwards and will
use the most specific value found. So you can define a global value
that applies to everything unless overridden, then you can redefine
the value for a specific Subnet, and redefine it for a specific pool,
and for a specific host.
ddns-domainname is a good example. You may well define a common value
(eg mydomain.com) as a global option. Then in one subnet you could
redefine it (eg sales.mydomain.com). You could create a group of host
declarations and have a different value for those hosts (eg
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