2 DHCP Servers

I have 2 networks

Voice network ----- DHCP Server
Data Network ------DHCP Server


These 2 networks are connected and can route between each other, I want each
network hosts to only get ip’s from there DHCP server and if 1 server goes
down only then should it be able to gert an address from the DHCP on the
other network how can I do this.


Thanks

Hello Ari,

If your router is able to forward DHCP requests just create on the other
DHCP server a scope for the remote site subnet and activate it if the server
is down. If it is allways active there is the chance that clients will get
leases from that server.

Best regards

Meinolf Weber
Disclaimer: This posting is provided "AS IS" with no warranties, and confers
no rights.
** Please do NOT email, only reply to Newsgroups
** HELP us help YOU!!! http://www.blakjak.demon.co.uk/mul_crss.htm


> I have 2 networks
>
> Voice network ----- DHCP Server
> Data Network ------DHCP Server
> These 2 networks are connected and can route between each other, I
> want each network hosts to only get ip’s from there DHCP server and if
> 1 server goes down only then should it be able to gert an address from
> the DHCP on the other network how can I do this.
>
> Thanks
>

Ari,
You need to create duplicate scopes for each network with non-overlapping
adress pool ranges (a common practice is to use 80/20 split - although
ultimately this depends on a number of factors, such as lease time or number
of clients to IP address space ratio) and the same set of reservations on
both DHCP servers. While this does not fully guarantee that the local DHCP
server will be used by all clients on the same subnet, it is fairly likely
that this will be the case.
As Meinolf has mentioned, in addition, your router needs to be configured as
DHCP relay agent (forwarding broadcast packets on UDP port 67 and 68, with
both interfaces pointing to the DHCP server on the "other" subnet)

hth
Marcin

As Meinolf has pointed out
"Ari" <> wrote in message
news:8D7A9740-E989-492F-B3D9-...
>I have 2 networks
>
> Voice network ----- DHCP Server
> Data Network ------DHCP Server
>
>
> These 2 networks are connected and can route between each other, I want
> each
> network hosts to only get ip's from there DHCP server and if 1 server goes
> down only then should it be able to gert an address from the DHCP on the
> other network how can I do this.
>
>
> Thanks
>

so it cannot be done automatically? is there an option to delay the DHCP
server response? so if server1 dosent respond only then it will take it from
server2?

"Marcin" wrote:

> Ari,
> You need to create duplicate scopes for each network with non-overlapping
> adress pool ranges (a common practice is to use 80/20 split - although
> ultimately this depends on a number of factors, such as lease time or number
> of clients to IP address space ratio) and the same set of reservations on
> both DHCP servers. While this does not fully guarantee that the local DHCP
> server will be used by all clients on the same subnet, it is fairly likely
> that this will be the case.
> As Meinolf has mentioned, in addition, your router needs to be configured as
> DHCP relay agent (forwarding broadcast packets on UDP port 67 and 68, with
> both interfaces pointing to the DHCP server on the "other" subnet)
>
> hth
> Marcin
>
> As Meinolf has pointed out
> "Ari" <> wrote in message
> news:8D7A9740-E989-492F-B3D9-...
> >I have 2 networks
> >
> > Voice network ----- DHCP Server
> > Data Network ------DHCP Server
> >
> >
> > These 2 networks are connected and can route between each other, I want
> > each
> > network hosts to only get ip's from there DHCP server and if 1 server goes
> > down only then should it be able to gert an address from the DHCP on the
> > other network how can I do this.
> >
> >
> > Thanks
> >
>
>
>

Ari - nothing available natively that I'm aware of (primarily due to the
nature of the process of obtaining DHCP lease)...

hth
Marcin

"Ari" <> wrote in message
news:4F0777E4-DC3F-410D-AB9E-...
> so it cannot be done automatically? is there an option to delay the DHCP
> server response? so if server1 dosent respond only then it will take it
> from
> server2?
>
> "Marcin" wrote:
>
>> Ari,
>> You need to create duplicate scopes for each network with non-overlapping
>> adress pool ranges (a common practice is to use 80/20 split - although
>> ultimately this depends on a number of factors, such as lease time or
>> number
>> of clients to IP address space ratio) and the same set of reservations on
>> both DHCP servers. While this does not fully guarantee that the local
>> DHCP
>> server will be used by all clients on the same subnet, it is fairly
>> likely
>> that this will be the case.
>> As Meinolf has mentioned, in addition, your router needs to be configured
>> as
>> DHCP relay agent (forwarding broadcast packets on UDP port 67 and 68,
>> with
>> both interfaces pointing to the DHCP server on the "other" subnet)
>>
>> hth
>> Marcin
>>
>> As Meinolf has pointed out
>> "Ari" <> wrote in message
>> news:8D7A9740-E989-492F-B3D9-...
>> >I have 2 networks
>> >
>> > Voice network ----- DHCP Server
>> > Data Network ------DHCP Server
>> >
>> >
>> > These 2 networks are connected and can route between each other, I want
>> > each
>> > network hosts to only get ip's from there DHCP server and if 1 server
>> > goes
>> > down only then should it be able to gert an address from the DHCP on
>> > the
>> > other network how can I do this.
>> >
>> >
>> > Thanks
>> >
>>
>>
>>

Hello Ari,

Never heard about, it's by design that if multiple DHCP servers are available,
the quickest one will answer.

Best regards

Meinolf Weber
Disclaimer: This posting is provided "AS IS" with no warranties, and confers
no rights.
** Please do NOT email, only reply to Newsgroups
** HELP us help YOU!!! http://www.blakjak.demon.co.uk/mul_crss.htm


> so it cannot be done automatically? is there an option to delay the
> DHCP server response? so if server1 dosent respond only then it will
> take it from server2?
>
> "Marcin" wrote:
>
>> Ari,
>> You need to create duplicate scopes for each network with
>> non-overlapping
>> adress pool ranges (a common practice is to use 80/20 split -
>> although
>> ultimately this depends on a number of factors, such as lease time or
>> number
>> of clients to IP address space ratio) and the same set of
>> reservations on
>> both DHCP servers. While this does not fully guarantee that the local
>> DHCP
>> server will be used by all clients on the same subnet, it is fairly
>> likely
>> that this will be the case.
>> As Meinolf has mentioned, in addition, your router needs to be
>> configured as
>> DHCP relay agent (forwarding broadcast packets on UDP port 67 and 68,
>> with
>> both interfaces pointing to the DHCP server on the "other" subnet)
>> hth
>> Marcin
>> As Meinolf has pointed out
>> "Ari" <> wrote in message
>> news:8D7A9740-E989-492F-B3D9-...
>>> I have 2 networks
>>>
>>> Voice network ----- DHCP Server
>>> Data Network ------DHCP Server
>>> These 2 networks are connected and can route between each other, I
>>> want
>>> each
>>> network hosts to only get ip's from there DHCP server and if 1
>>> server goes
>>> down only then should it be able to gert an address from the DHCP on
>>> the
>>> other network how can I do this.
>>> Thanks
>>>

You can cluster DHCP if you setup shared disk between the 2 hosts, clustering
you would put both scopes on a single resource node and that resource node
could float between the 2 clustered hosts.
--
Chief Putz


"Meinolf Weber" wrote:

> Hello Ari,
>
> Never heard about, it's by design that if multiple DHCP servers are available,
> the quickest one will answer.
>
> Best regards
>
> Meinolf Weber
> Disclaimer: This posting is provided "AS IS" with no warranties, and confers
> no rights.
> ** Please do NOT email, only reply to Newsgroups
> ** HELP us help YOU!!! http://www.blakjak.demon.co.uk/mul_crss.htm
>
>
> > so it cannot be done automatically? is there an option to delay the
> > DHCP server response? so if server1 dosent respond only then it will
> > take it from server2?
> >
> > "Marcin" wrote:
> >
> >> Ari,
> >> You need to create duplicate scopes for each network with
> >> non-overlapping
> >> adress pool ranges (a common practice is to use 80/20 split -
> >> although
> >> ultimately this depends on a number of factors, such as lease time or
> >> number
> >> of clients to IP address space ratio) and the same set of
> >> reservations on
> >> both DHCP servers. While this does not fully guarantee that the local
> >> DHCP
> >> server will be used by all clients on the same subnet, it is fairly
> >> likely
> >> that this will be the case.
> >> As Meinolf has mentioned, in addition, your router needs to be
> >> configured as
> >> DHCP relay agent (forwarding broadcast packets on UDP port 67 and 68,
> >> with
> >> both interfaces pointing to the DHCP server on the "other" subnet)
> >> hth
> >> Marcin
> >> As Meinolf has pointed out
> >> "Ari" <> wrote in message
> >> news:8D7A9740-E989-492F-B3D9-...
> >>> I have 2 networks
> >>>
> >>> Voice network ----- DHCP Server
> >>> Data Network ------DHCP Server
> >>> These 2 networks are connected and can route between each other, I
> >>> want
> >>> each
> >>> network hosts to only get ip's from there DHCP server and if 1
> >>> server goes
> >>> down only then should it be able to gert an address from the DHCP on
> >>> the
> >>> other network how can I do this.
> >>> Thanks
> >>>
>
>
>