Re: Move DHCP Service

On 05/11/2009, at 6:24 AM, Alexander Bassi wrote:

On Nov 4, 2009, at 1:02 PM, Jeff C. Anderson wrote:

We need to move our current/active DHCP service from its present
MacOSX 10.5.8 Xserve to different physical Xserve, Also running
MacOS Server 10.5.8. Exporting and importing the DHCP service
settings to preserve all of the subnets is quite straightforward.
However, does anyone know if it is possible to actually move the
existing client database, so that client machines will not acquire
totally new addresses...which I suspect will play havoc with ARD
computer lists. Even the location of the client database remains
a mystery to us so far...

Thanks for any suggestions...

Jeff A

Jeff,

The DHCP list is stored in:

/var/db/dhcpd_leases

As per the details below, there are definitely some things to consider, not least of which are:

- the changeover time

- The permissions on the lease file

- Getting the serveradmin settings the same, but adjusting details like the router etc.

but this is the file to take across.

Old DHCP server = DHCP(a);
New DHCP server = DHCP(b);

"Client database" - as in, the DHCP leases the DHCP service compares to it's clients' MAC addresses?

Is DHCP(b) also now hosting DNS? It DHCP(b) acting as the new router/gateway? If any of the following information changes, you will have to renew each DHCP lease for all clients: Subnet, Router, Search Domains, DNS Servers, and/or LDAP info. If it's identical, each client should ask the network for a new address, to which, the new DHCP server will provide the same info.

DORA:

* Discover - "Is there a DHCP server out there?"
* Offer - [DHCP(b)] Why yes, here's an IP address and some other info.
* Respond - "Just to confirm, *this* is the info you're providing me, right?"
* Acknowledge - [DHCP(b)] Yes. Don't ask me again for n hours. (where n represents the time-to-live on the DHCP lease)

BTW, what's happening to DHCP(a)?

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References:
	>Move DHCP Service (From: "Jeff C. Anderson" <email@hidden>)
	>Re: Move DHCP Service (From: Alexander Bassi <email@hidden>)