What is so significant about the 80/20 rule for DHCP? Microsoft
recommends you host 80% of a zone on one DHCP server and the other 20%
on a different server. Why not 50/50? 50/50 seems more logical to me...

If anybody knows what the realm of this 80/20 rule is, please let me
know.

Thanks,
Brian

http://www.google.com/search?hl=en&q...+rule+for+DHCP


Techhead wrote:

> What is so significant about the 80/20 rule for DHCP? Microsoft
> recommends you host 80% of a zone on one DHCP server and the other 20%
> on a different server. Why not 50/50? 50/50 seems more logical to me...
>
> If anybody knows what the realm of this 80/20 rule is, please let me
> know.
>
> Thanks,
> Brian
>

It appears that this rule only applies to multiple subnets but what
about running 2 DHCP servers on the same subnet?

No can do.

Techhead wrote:
> It appears that this rule only applies to multiple subnets but what
> about running 2 DHCP servers on the same subnet?
>

Sure you can. Run both in the same subnet, use excisions on each server to
exclude the range of addresses the other is giving out. Configure both for,
say, 192.168.1.x addressing; then on one server exclude the addresses
192.168.1.200-255 and on the other exclude the addresses 192.168.1.1-199 so
they don't step on each other's toes.

I don't consider this wise unless you're running a really big network (in
which case you probably have multiple ranges anyway) but it surely can be
done.

--
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* PLEASE post all messages and replies in the newsgroups
* for the benefit of all. Private mail is usually not replied to.
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"Bob I" <(E-Mail Removed)> wrote in message
news:ewz$(E-Mail Removed)...
> No can do.
>
> Techhead wrote:
>> It appears that this rule only applies to multiple subnets but what
>> about running 2 DHCP servers on the same subnet?
>>
>

Wouldn't that cause a problem with the system changing the IP address of
a clients at renew time?

Richard G. Harper wrote:

> Sure you can. Run both in the same subnet, use excisions on each server to
> exclude the range of addresses the other is giving out. Configure both for,
> say, 192.168.1.x addressing; then on one server exclude the addresses
> 192.168.1.200-255 and on the other exclude the addresses 192.168.1.1-199 so
> they don't step on each other's toes.
>
> I don't consider this wise unless you're running a really big network (in
> which case you probably have multiple ranges anyway) but it surely can be
> done.
>

One live dhcp server per subnet. Is it not?


"Bob I" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> Wouldn't that cause a problem with the system changing the IP address of
> a clients at renew time?
>
> Richard G. Harper wrote:
>
> > Sure you can. Run both in the same subnet, use excisions on each server
to
> > exclude the range of addresses the other is giving out. Configure both
for,
> > say, 192.168.1.x addressing; then on one server exclude the addresses
> > 192.168.1.200-255 and on the other exclude the addresses 192.168.1.1-199
so
> > they don't step on each other's toes.
> >
> > I don't consider this wise unless you're running a really big network
(in
> > which case you probably have multiple ranges anyway) but it surely can
be
> > done.
> >
>

That was my belief. (let's say recommendation )

Andrew Story wrote:

> One live dhcp server per subnet. Is it not?
>
>
> "Bob I" <(E-Mail Removed)> wrote in message
> news:(E-Mail Removed)...
>
>>Wouldn't that cause a problem with the system changing the IP address of
>>a clients at renew time?
>>
>>Richard G. Harper wrote:
>>
>>
>>>Sure you can. Run both in the same subnet, use excisions on each server
>
> to
>
>>>exclude the range of addresses the other is giving out. Configure both
>
> for,
>
>>>say, 192.168.1.x addressing; then on one server exclude the addresses
>>>192.168.1.200-255 and on the other exclude the addresses 192.168.1.1-199
>
> so
>
>>>they don't step on each other's toes.
>>>
>>>I don't consider this wise unless you're running a really big network
>
> (in
>
>>>which case you probably have multiple ranges anyway) but it surely can
>
> be
>
>>>done.
>>>
>>
>
>

Yes, but it's not going to give out an address thats excluded in the
zone and is offered by a DIFFERENT dhcp server for the SAME zone. You
can have multiple DHCP servers running on 1 subnet. Trust me, I'm doing
it right now with no problems. I'm just wondering about the 80/20 rule.

This is what happens when you have more than on DHCP server on a single
subnet. Which ever DHCP server responds first to the client request,
serve's the request. When a client renews a lease, it tries to renew
from the last DHCP server it received an IP from, otherwise it sends a
broadcast and whichever server responds first again, serve's the lease.
If the first DHCP server in my subnet as leased out all of it's IP's,
then the second DHCP server will only respond to client requests.

As long as the 1st DHCP server does not assign the same addresses as
the 2nd server, you are fine.