Question about changing DNS servers and DHCP

If I'm installing a new local DNS server and change the DHCP server to
assign that as the primary DNS with the old DNS server as an alternate,
will the DHCP client computers get the information updated when they
make their automatic request to renew the lease, or do I have to restart
said clients before they'll use that updated information?

Some of the computers are rarely shut down or restarted, so I'd rather
not wait weeks or even months before they start using the new server,
but waiting a few days for them to renew the one week lease sounds
perfect while I'm making sure there are no glitches in the new setup I
haven't spotted during my inital testing.

SlickRCBD <(E-Mail Removed)> wrote:

> If I'm installing a new local DNS server and change the DHCP server to
> assign that as the primary DNS with the old DNS server as an alternate,
> will the DHCP client computers get the information updated when they
> make their automatic request to renew the lease, or do I have to restart
> said clients before they'll use that updated information?

Depends on the OS and on the DHCP settings - but you can force the issue
by making sure that all machines in the network (downstream from your
DHCP server) are set to use that server (which in smaller networks would
often be the router) as their DNS, then changing the DNS settings at the
DHCP server will, of course, be in effect immediately. If the clients
have their own DNS settings, however, then they will never change and
need to be changed manually.

Al

On Sat, 10 Feb 2007 02:09:37 -0600, SlickRCBD <(E-Mail Removed)>
wrote:

>If I'm installing a new local DNS server and change the DHCP server to
>assign that as the primary DNS with the old DNS server as an alternate,
>will the DHCP client computers get the information updated when they
>make their automatic request to renew the lease, or do I have to restart
>said clients before they'll use that updated information?
>
>Some of the computers are rarely shut down or restarted, so I'd rather
>not wait weeks or even months before they start using the new server,
>but waiting a few days for them to renew the one week lease sounds
>perfect while I'm making sure there are no glitches in the new setup I
>haven't spotted during my inital testing.

If the clients are using DHCP now, at each client open a command
session and enter the commands:

ipconfig /release
ipconfig /renew

ipconfig /all

The first two commands will re-load the (now changed) network
settings, the last one will confirm the changes.

PeterD wrote:
> On Sat, 10 Feb 2007 02:09:37 -0600, SlickRCBD <(E-Mail Removed)>
> wrote:
>
>
>>If I'm installing a new local DNS server and change the DHCP server to
>>assign that as the primary DNS with the old DNS server as an alternate,
>>will the DHCP client computers get the information updated when they
>>make their automatic request to renew the lease, or do I have to restart
>>said clients before they'll use that updated information?
>>
>>Some of the computers are rarely shut down or restarted, so I'd rather
>>not wait weeks or even months before they start using the new server,
>>but waiting a few days for them to renew the one week lease sounds
>>perfect while I'm making sure there are no glitches in the new setup I
>>haven't spotted during my inital testing.
>
>
> If the clients are using DHCP now, at each client open a command
> session and enter the commands:
>
> ipconfig /release
> ipconfig /renew
>
> ipconfig /all
>
> The first two commands will re-load the (now changed) network
> settings, the last one will confirm the changes.
DNS information is assigned by the DHCP server. I knew about the quoted
commands, and that would work, but my question was if I were to do
nothing, would the DNS information be updated automatically when it
tries to renew the lease, or would I HAVE to use those commands to force
it to update?