Multi DHCP Scopes across Fiber M.A.N.

Windows 2003 D.C. Server Fully patched.
4 Cisco 1841 routers holding fiberoptic metro area network connections

Main Office: 192.168.100.0/24 DHCP managed by DC
Office 2 192.168.101.0/24 DHCP managed by Cisco router
Office 3 192.168.102.0/24 DHCP managed by Cisco router
Office 4 192.168.103.0/24 DHCP managed by Cisco router

All four locations connected together via fiber optic metro area network on
a private VLAN.


I have a domain controller issuing DHCP at my main location. At each of the
other 3 locations, the Cisco 1841 router at that location is acting as DHCP
server for that local subnet. I would prefer to centralize DHCP on the
domain controller, and still be able to keep my subnet addressing scheme as
is. I know that my routers can function as DHCP relays, but this is only one
of the options I have studied. Im not clear on how to structure this so that
each machines in each office receive an address that is correct for their
location. Some articles have inferred that RRAS would be necessary as well.
If someone can give a basic illustration of how this would work and which
network management applications have to be in the loop, i can go from there.
TIA for any advice or informative articles.

Sam,
Set up the scopes on the central DC.
Set an ip helper address on each router to forward the DHCP requests to the
DC. The central DHCP server will respond to requests with an address in the
scope where the request came from.
Anthony
http://www.airdesk.co.uk



"SeriousSam" <(E-Mail Removed)> wrote in message
news:ux4$(E-Mail Removed)...
> Windows 2003 D.C. Server Fully patched.
> 4 Cisco 1841 routers holding fiberoptic metro area network connections
>
> Main Office: 192.168.100.0/24 DHCP managed by DC
> Office 2 192.168.101.0/24 DHCP managed by Cisco router
> Office 3 192.168.102.0/24 DHCP managed by Cisco router
> Office 4 192.168.103.0/24 DHCP managed by Cisco router
>
> All four locations connected together via fiber optic metro area network
> on a private VLAN.
>
>
> I have a domain controller issuing DHCP at my main location. At each of
> the other 3 locations, the Cisco 1841 router at that location is acting as
> DHCP server for that local subnet. I would prefer to centralize DHCP on
> the domain controller, and still be able to keep my subnet addressing
> scheme as is. I know that my routers can function as DHCP relays, but this
> is only one of the options I have studied. Im not clear on how to
> structure this so that each machines in each office receive an address
> that is correct for their location. Some articles have inferred that RRAS
> would be necessary as well. If someone can give a basic illustration of
> how this would work and which network management applications have to be
> in the loop, i can go from there. TIA for any advice or informative
> articles.
>

Sweet! Thanks for the direction Anthony. I checked out the IP Helper set up
in the routers and it looks like it should be a clean and fairly easy way to
go. I wondered what exactly the IP Helper function was for. Have a great
day.


"Anthony" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> Sam,
> Set up the scopes on the central DC.
> Set an ip helper address on each router to forward the DHCP requests to
> the DC. The central DHCP server will respond to requests with an address
> in the scope where the request came from.
> Anthony
> http://www.airdesk.co.uk
>
>
>
> "SeriousSam" <(E-Mail Removed)> wrote in message
> news:ux4$(E-Mail Removed)...
>> Windows 2003 D.C. Server Fully patched.
>> 4 Cisco 1841 routers holding fiberoptic metro area network connections
>>
>> Main Office: 192.168.100.0/24 DHCP managed by DC
>> Office 2 192.168.101.0/24 DHCP managed by Cisco router
>> Office 3 192.168.102.0/24 DHCP managed by Cisco router
>> Office 4 192.168.103.0/24 DHCP managed by Cisco router
>>
>> All four locations connected together via fiber optic metro area network
>> on a private VLAN.
>>
>>
>> I have a domain controller issuing DHCP at my main location. At each of
>> the other 3 locations, the Cisco 1841 router at that location is acting
>> as DHCP server for that local subnet. I would prefer to centralize DHCP
>> on the domain controller, and still be able to keep my subnet addressing
>> scheme as is. I know that my routers can function as DHCP relays, but
>> this is only one of the options I have studied. Im not clear on how to
>> structure this so that each machines in each office receive an address
>> that is correct for their location. Some articles have inferred that RRAS
>> would be necessary as well. If someone can give a basic illustration of
>> how this would work and which network management applications have to be
>> in the loop, i can go from there. TIA for any advice or informative
>> articles.
>>
>
>

Its a pleasure
"SeriousSam" <(E-Mail Removed)> wrote in message
news:%(E-Mail Removed)...
> Sweet! Thanks for the direction Anthony. I checked out the IP Helper set
> up in the routers and it looks like it should be a clean and fairly easy
> way to go. I wondered what exactly the IP Helper function was for. Have a
> great day.
>
>
> "Anthony" <(E-Mail Removed)> wrote in message
> news:(E-Mail Removed)...
>> Sam,
>> Set up the scopes on the central DC.
>> Set an ip helper address on each router to forward the DHCP requests to
>> the DC. The central DHCP server will respond to requests with an address
>> in the scope where the request came from.
>> Anthony
>> http://www.airdesk.co.uk
>>
>>
>>
>> "SeriousSam" <(E-Mail Removed)> wrote in message
>> news:ux4$(E-Mail Removed)...
>>> Windows 2003 D.C. Server Fully patched.
>>> 4 Cisco 1841 routers holding fiberoptic metro area network connections
>>>
>>> Main Office: 192.168.100.0/24 DHCP managed by DC
>>> Office 2 192.168.101.0/24 DHCP managed by Cisco router
>>> Office 3 192.168.102.0/24 DHCP managed by Cisco router
>>> Office 4 192.168.103.0/24 DHCP managed by Cisco router
>>>
>>> All four locations connected together via fiber optic metro area network
>>> on a private VLAN.
>>>
>>>
>>> I have a domain controller issuing DHCP at my main location. At each of
>>> the other 3 locations, the Cisco 1841 router at that location is acting
>>> as DHCP server for that local subnet. I would prefer to centralize DHCP
>>> on the domain controller, and still be able to keep my subnet addressing
>>> scheme as is. I know that my routers can function as DHCP relays, but
>>> this is only one of the options I have studied. Im not clear on how to
>>> structure this so that each machines in each office receive an address
>>> that is correct for their location. Some articles have inferred that
>>> RRAS would be necessary as well. If someone can give a basic
>>> illustration of how this would work and which network management
>>> applications have to be in the loop, i can go from there. TIA for any
>>> advice or informative articles.
>>>
>>
>>
>
>

Keep in mind that centralizing DHCP is potentially a bad idea and will be
disaster if the fiber goes down. The client will not get thier address and
will default to the 169 auto addressing and the LAN at the site would
collapse.

The best solution is a Windows Server at each location that is a DC/DNS and
a DHCP. You use the AD Site Object to maintain the AD replication over the
slow link. This way the system will still function if the fiber goes down.

--
Phillip Windell
www.wandtv.com

The views expressed, are my own and not those of my employer, or Microsoft,
or anyone else associated with me, including my cats.
-----------------------------------------------------
Understanding the ISA 2004 Access Rule Processing
http://www.isaserver.org/articles/IS...cessRules.html

Troubleshooting Client Authentication on Access Rules in ISA Server 2004
http://download.microsoft.com/downlo...7/ts_rules.doc

Microsoft Internet Security & Acceleration Server: Partners
http://www.microsoft.com/isaserver/partners/default.asp

Microsoft ISA Server Partners: Partner Hardware Solutions
http://www.microsoft.com/forefront/e...epartners.mspx
-----------------------------------------------------

"SeriousSam" <(E-Mail Removed)> wrote in message
news:%(E-Mail Removed)...
> Sweet! Thanks for the direction Anthony. I checked out the IP Helper set
> up in the routers and it looks like it should be a clean and fairly easy
> way to go. I wondered what exactly the IP Helper function was for. Have a
> great day.
>
>
> "Anthony" <(E-Mail Removed)> wrote in message
> news:(E-Mail Removed)...
>> Sam,
>> Set up the scopes on the central DC.
>> Set an ip helper address on each router to forward the DHCP requests to
>> the DC. The central DHCP server will respond to requests with an address
>> in the scope where the request came from.
>> Anthony
>> http://www.airdesk.co.uk
>>
>>
>>
>> "SeriousSam" <(E-Mail Removed)> wrote in message
>> news:ux4$(E-Mail Removed)...
>>> Windows 2003 D.C. Server Fully patched.
>>> 4 Cisco 1841 routers holding fiberoptic metro area network connections
>>>
>>> Main Office: 192.168.100.0/24 DHCP managed by DC
>>> Office 2 192.168.101.0/24 DHCP managed by Cisco router
>>> Office 3 192.168.102.0/24 DHCP managed by Cisco router
>>> Office 4 192.168.103.0/24 DHCP managed by Cisco router
>>>
>>> All four locations connected together via fiber optic metro area network
>>> on a private VLAN.
>>>
>>>
>>> I have a domain controller issuing DHCP at my main location. At each of
>>> the other 3 locations, the Cisco 1841 router at that location is acting
>>> as DHCP server for that local subnet. I would prefer to centralize DHCP
>>> on the domain controller, and still be able to keep my subnet addressing
>>> scheme as is. I know that my routers can function as DHCP relays, but
>>> this is only one of the options I have studied. Im not clear on how to
>>> structure this so that each machines in each office receive an address
>>> that is correct for their location. Some articles have inferred that
>>> RRAS would be necessary as well. If someone can give a basic
>>> illustration of how this would work and which network management
>>> applications have to be in the loop, i can go from there. TIA for any
>>> advice or informative articles.
>>>
>>
>>
>
>

You can counter a bit the dhcp trouble by having long lease of 8 or even 24
hours, so you have time to repair.

--
Cordialement,
Mathieu CHATEAU
http://lordoftheping.blogspot.com


"Phillip Windell" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> Keep in mind that centralizing DHCP is potentially a bad idea and will be
> disaster if the fiber goes down. The client will not get thier address
> and will default to the 169 auto addressing and the LAN at the site would
> collapse.
>
> The best solution is a Windows Server at each location that is a DC/DNS
> and a DHCP. You use the AD Site Object to maintain the AD replication
> over the slow link. This way the system will still function if the fiber
> goes down.
>
> --
> Phillip Windell
> www.wandtv.com
>
> The views expressed, are my own and not those of my employer, or
> Microsoft, or anyone else associated with me, including my cats.
> -----------------------------------------------------
> Understanding the ISA 2004 Access Rule Processing
> http://www.isaserver.org/articles/IS...cessRules.html
>
> Troubleshooting Client Authentication on Access Rules in ISA Server 2004
> http://download.microsoft.com/downlo...7/ts_rules.doc
>
> Microsoft Internet Security & Acceleration Server: Partners
> http://www.microsoft.com/isaserver/partners/default.asp
>
> Microsoft ISA Server Partners: Partner Hardware Solutions
> http://www.microsoft.com/forefront/e...epartners.mspx
> -----------------------------------------------------
>
> "SeriousSam" <(E-Mail Removed)> wrote in message
> news:%(E-Mail Removed)...
>> Sweet! Thanks for the direction Anthony. I checked out the IP Helper set
>> up in the routers and it looks like it should be a clean and fairly easy
>> way to go. I wondered what exactly the IP Helper function was for. Have a
>> great day.
>>
>>
>> "Anthony" <(E-Mail Removed)> wrote in message
>> news:(E-Mail Removed)...
>>> Sam,
>>> Set up the scopes on the central DC.
>>> Set an ip helper address on each router to forward the DHCP requests to
>>> the DC. The central DHCP server will respond to requests with an address
>>> in the scope where the request came from.
>>> Anthony
>>> http://www.airdesk.co.uk
>>>
>>>
>>>
>>> "SeriousSam" <(E-Mail Removed)> wrote in message
>>> news:ux4$(E-Mail Removed)...
>>>> Windows 2003 D.C. Server Fully patched.
>>>> 4 Cisco 1841 routers holding fiberoptic metro area network connections
>>>>
>>>> Main Office: 192.168.100.0/24 DHCP managed by DC
>>>> Office 2 192.168.101.0/24 DHCP managed by Cisco router
>>>> Office 3 192.168.102.0/24 DHCP managed by Cisco router
>>>> Office 4 192.168.103.0/24 DHCP managed by Cisco router
>>>>
>>>> All four locations connected together via fiber optic metro area
>>>> network on a private VLAN.
>>>>
>>>>
>>>> I have a domain controller issuing DHCP at my main location. At each of
>>>> the other 3 locations, the Cisco 1841 router at that location is acting
>>>> as DHCP server for that local subnet. I would prefer to centralize DHCP
>>>> on the domain controller, and still be able to keep my subnet
>>>> addressing scheme as is. I know that my routers can function as DHCP
>>>> relays, but this is only one of the options I have studied. Im not
>>>> clear on how to structure this so that each machines in each office
>>>> receive an address that is correct for their location. Some articles
>>>> have inferred that RRAS would be necessary as well. If someone can give
>>>> a basic illustration of how this would work and which network
>>>> management applications have to be in the loop, i can go from there.
>>>> TIA for any advice or informative articles.
>>>>
>>>
>>>
>>
>>
>
>

Yes, that will help as long as the lease isn't trying to get renewed right
when the line is down.

--
Phillip Windell
www.wandtv.com

The views expressed, are my own and not those of my employer, or Microsoft,
or anyone else associated with me, including my cats.
-----------------------------------------------------

"Mathieu CHATEAU" <(E-Mail Removed)> wrote in message
news:%(E-Mail Removed)...
> You can counter a bit the dhcp trouble by having long lease of 8 or even
> 24 hours, so you have time to repair.
>
> --
> Cordialement,
> Mathieu CHATEAU
> http://lordoftheping.blogspot.com
>
>
> "Phillip Windell" <(E-Mail Removed)> wrote in message
> news:(E-Mail Removed)...
>> Keep in mind that centralizing DHCP is potentially a bad idea and will be
>> disaster if the fiber goes down. The client will not get thier address
>> and will default to the 169 auto addressing and the LAN at the site would
>> collapse.
>>
>> The best solution is a Windows Server at each location that is a DC/DNS
>> and a DHCP. You use the AD Site Object to maintain the AD replication
>> over the slow link. This way the system will still function if the fiber
>> goes down.
>>
>> --
>> Phillip Windell
>> www.wandtv.com
>>
>> The views expressed, are my own and not those of my employer, or
>> Microsoft, or anyone else associated with me, including my cats.
>> -----------------------------------------------------
>> Understanding the ISA 2004 Access Rule Processing
>> http://www.isaserver.org/articles/IS...cessRules.html
>>
>> Troubleshooting Client Authentication on Access Rules in ISA Server 2004
>> http://download.microsoft.com/downlo...7/ts_rules.doc
>>
>> Microsoft Internet Security & Acceleration Server: Partners
>> http://www.microsoft.com/isaserver/partners/default.asp
>>
>> Microsoft ISA Server Partners: Partner Hardware Solutions
>> http://www.microsoft.com/forefront/e...epartners.mspx
>> -----------------------------------------------------
>>
>> "SeriousSam" <(E-Mail Removed)> wrote in message
>> news:%(E-Mail Removed)...
>>> Sweet! Thanks for the direction Anthony. I checked out the IP Helper set
>>> up in the routers and it looks like it should be a clean and fairly easy
>>> way to go. I wondered what exactly the IP Helper function was for. Have
>>> a great day.
>>>
>>>
>>> "Anthony" <(E-Mail Removed)> wrote in message
>>> news:(E-Mail Removed)...
>>>> Sam,
>>>> Set up the scopes on the central DC.
>>>> Set an ip helper address on each router to forward the DHCP requests to
>>>> the DC. The central DHCP server will respond to requests with an
>>>> address in the scope where the request came from.
>>>> Anthony
>>>> http://www.airdesk.co.uk
>>>>
>>>>
>>>>
>>>> "SeriousSam" <(E-Mail Removed)> wrote in message
>>>> news:ux4$(E-Mail Removed)...
>>>>> Windows 2003 D.C. Server Fully patched.
>>>>> 4 Cisco 1841 routers holding fiberoptic metro area network connections
>>>>>
>>>>> Main Office: 192.168.100.0/24 DHCP managed by DC
>>>>> Office 2 192.168.101.0/24 DHCP managed by Cisco router
>>>>> Office 3 192.168.102.0/24 DHCP managed by Cisco router
>>>>> Office 4 192.168.103.0/24 DHCP managed by Cisco router
>>>>>
>>>>> All four locations connected together via fiber optic metro area
>>>>> network on a private VLAN.
>>>>>
>>>>>
>>>>> I have a domain controller issuing DHCP at my main location. At each
>>>>> of the other 3 locations, the Cisco 1841 router at that location is
>>>>> acting as DHCP server for that local subnet. I would prefer to
>>>>> centralize DHCP on the domain controller, and still be able to keep my
>>>>> subnet addressing scheme as is. I know that my routers can function as
>>>>> DHCP relays, but this is only one of the options I have studied. Im
>>>>> not clear on how to structure this so that each machines in each
>>>>> office receive an address that is correct for their location. Some
>>>>> articles have inferred that RRAS would be necessary as well. If
>>>>> someone can give a basic illustration of how this would work and which
>>>>> network management applications have to be in the loop, i can go from
>>>>> there. TIA for any advice or informative articles.
>>>>>
>>>>
>>>>
>>>
>>>
>>
>>
>

You guys are right about it being best to have a backup DC and DHCP server
at each location. Its a scenario I have been trying to find a reasonable
solution to for some time. The thing is, our remote offices have two
applications that have to run for us to even operate. One of them is carried
in to our main office on a T1 line and the other offices hit that connection
via the fiber. The other is a central server handling our customer service
application. If the fiber goes down, there is no reason for PCs at other
locations to even be turned on, since those apps wouldnt be available
anyway. The only real redundancy for the app via T1 is to run frame relay
circuits to every location, which is financially out of the question. I have
considered setting up wireless links to run in case of emergency fiber
failure, but wireless long distance link isnt really an option here. Our
board of directors won't stand for the idea of our data "floating around in
the air", regardless of 3DES, etc. LOL. Anyway, its life. Sometimes ya just
gotta throw the dice!


"Phillip Windell" <(E-Mail Removed)> wrote in message
news:O2s$$(E-Mail Removed)...
> Yes, that will help as long as the lease isn't trying to get renewed right
> when the line is down.
>
> --
> Phillip Windell
> www.wandtv.com
>
> The views expressed, are my own and not those of my employer, or
> Microsoft, or anyone else associated with me, including my cats.
> -----------------------------------------------------
>
> "Mathieu CHATEAU" <(E-Mail Removed)> wrote in message
> news:%(E-Mail Removed)...
>> You can counter a bit the dhcp trouble by having long lease of 8 or even
>> 24 hours, so you have time to repair.
>>
>> --
>> Cordialement,
>> Mathieu CHATEAU
>> http://lordoftheping.blogspot.com
>>
>>
>> "Phillip Windell" <(E-Mail Removed)> wrote in message
>> news:(E-Mail Removed)...
>>> Keep in mind that centralizing DHCP is potentially a bad idea and will
>>> be disaster if the fiber goes down. The client will not get thier
>>> address and will default to the 169 auto addressing and the LAN at the
>>> site would collapse.
>>>
>>> The best solution is a Windows Server at each location that is a DC/DNS
>>> and a DHCP. You use the AD Site Object to maintain the AD replication
>>> over the slow link. This way the system will still function if the
>>> fiber goes down.
>>>
>>> --
>>> Phillip Windell
>>> www.wandtv.com
>>>
>>> The views expressed, are my own and not those of my employer, or
>>> Microsoft, or anyone else associated with me, including my cats.
>>> -----------------------------------------------------
>>> Understanding the ISA 2004 Access Rule Processing
>>> http://www.isaserver.org/articles/IS...cessRules.html
>>>
>>> Troubleshooting Client Authentication on Access Rules in ISA Server 2004
>>> http://download.microsoft.com/downlo...7/ts_rules.doc
>>>
>>> Microsoft Internet Security & Acceleration Server: Partners
>>> http://www.microsoft.com/isaserver/partners/default.asp
>>>
>>> Microsoft ISA Server Partners: Partner Hardware Solutions
>>> http://www.microsoft.com/forefront/e...epartners.mspx
>>> -----------------------------------------------------
>>>
>>> "SeriousSam" <(E-Mail Removed)> wrote in message
>>> news:%(E-Mail Removed)...
>>>> Sweet! Thanks for the direction Anthony. I checked out the IP Helper
>>>> set up in the routers and it looks like it should be a clean and fairly
>>>> easy way to go. I wondered what exactly the IP Helper function was for.
>>>> Have a great day.
>>>>
>>>>
>>>> "Anthony" <(E-Mail Removed)> wrote in message
>>>> news:(E-Mail Removed)...
>>>>> Sam,
>>>>> Set up the scopes on the central DC.
>>>>> Set an ip helper address on each router to forward the DHCP requests
>>>>> to the DC. The central DHCP server will respond to requests with an
>>>>> address in the scope where the request came from.
>>>>> Anthony
>>>>> http://www.airdesk.co.uk
>>>>>
>>>>>
>>>>>
>>>>> "SeriousSam" <(E-Mail Removed)> wrote in message
>>>>> news:ux4$(E-Mail Removed)...
>>>>>> Windows 2003 D.C. Server Fully patched.
>>>>>> 4 Cisco 1841 routers holding fiberoptic metro area network
>>>>>> connections
>>>>>>
>>>>>> Main Office: 192.168.100.0/24 DHCP managed by DC
>>>>>> Office 2 192.168.101.0/24 DHCP managed by Cisco router
>>>>>> Office 3 192.168.102.0/24 DHCP managed by Cisco router
>>>>>> Office 4 192.168.103.0/24 DHCP managed by Cisco router
>>>>>>
>>>>>> All four locations connected together via fiber optic metro area
>>>>>> network on a private VLAN.
>>>>>>
>>>>>>
>>>>>> I have a domain controller issuing DHCP at my main location. At each
>>>>>> of the other 3 locations, the Cisco 1841 router at that location is
>>>>>> acting as DHCP server for that local subnet. I would prefer to
>>>>>> centralize DHCP on the domain controller, and still be able to keep
>>>>>> my subnet addressing scheme as is. I know that my routers can
>>>>>> function as DHCP relays, but this is only one of the options I have
>>>>>> studied. Im not clear on how to structure this so that each machines
>>>>>> in each office receive an address that is correct for their location.
>>>>>> Some articles have inferred that RRAS would be necessary as well. If
>>>>>> someone can give a basic illustration of how this would work and
>>>>>> which network management applications have to be in the loop, i can
>>>>>> go from there. TIA for any advice or informative articles.
>>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>
>>>
>>
>
>