Windows multiple DNS entries

[Kevin Darcy]

Vineesh Viswanath Iyer wrote:
> Hi all 
>
> I have got dhcp setup on a cisco switch . 
>
> When a new machine is switched on , it get's a dhcp address and 
> registers in the dns , this works fine , but when the lease expires , 
> or if for some reason if the same machine get's a new ip address, the 
> DNS is not recognising this dynamically . It will resolve to the first 
> IP address which the PC has got . 
>
>
>
> could you please let me know if there is any setting that i should be 
> looking at .
>
Does it *never* see the change? If that's the case, then you'd need to 
look at the client settings, since you indicated that the client is 
updating DNS directly. I've never dealt with clients that update DNS 
directly from DHCP lease activity, but maybe there's some "update once 
and then never again" option that you have turned on accidentally. (In 
case you can't read between the lines, I'm not a big fan of the concept 
of throwing open one's DNS to be updated directly by DHCP clients. I 
much prefer the DHCP server to do these updates, if DNS needs to be 
updated at all for dynamically-addressed clients).

Or, is it just _slow_ for the change to become visible? In that case, 
I'd look at your zone-transfer and NOTIFY settings (which govern how 
long the change takes to get from the master of the relevant zone(s), 
where the Dynamic Update is made, out to all of the slaves) and/or the 
TTL setting on the records in question (which govern how long the data 
is cached on nameservers/resolvers which are neither the master nor any 
of its slaves). If the client is making the Dynamic Update directly, 
then it would set the TTL on the record(s), so look at the settings there.

                                                                         
                                 - Kevin