DHCPD , dhcp relays on a large network

[Glenn Satchell]

Hi Alex

Try adding an empty declaration for the missing subnet(s), eg:

subnet 192.168.1.0 netmask 255.255.255.0 { }
subnet 192.168.2.0 netmask 255.255.255.0 { }
and so on.

Can you cut and paste the *exact* startup messages from dhcpd?

It may also be necessary to post your dhcpd.conf. Note this file must
accurately describe your network topology.

Shared networks are described in the dhcpd.conf man page, search for
'shared-network' but it doesn't seem like you need that if everything
is separate vlans.

regards,
-glenn
--
Glenn Satchell     mailto:glenn.satchell at uniq.com.au | Some days we are
Uniq Advances Pty Ltd         http://www.uniq.com.au | the flies;  some
PO Box 70 Paddington NSW Australia 2021              | days we  are the
tel:0409-458-580  tel:02-9380-6360  fax:02-9380-6416 | windscreens...

>From: "Alexandru Coseru" <alexandru.coseru at totaltelecom.ro>
>To: <dhcp-users at isc.org>
>Subject: Re: DHCPD , dhcp relays  on a large network
>Date: Fri, 10 Nov 2006 14:09:02 +0200
>
>The ideea is that   each switch has a subnet  attached to it..
>
>On the backbone   , I have the dhcpd server..
>
>The dhcpd server is not directly attached to the subnets , it has to go 
>through a layer3 route to reach them..
>
>
>                 10.1.1.0/24                                 192.168.1.0/24
>srv1     ----------------     L3 SW  A     -------------------------  
>subnet1
>
>
>The L3 SW A  has  DHCPD relay options enabled  ,  so the DHCPD requests 
>arrives   on  srv1.
>But srv1  has no knowledge  of  class 192.168.1.0/24  , and the server 
>cannot be started  (Error:   No subnet declaration for 192.168.1.0/24).
>The server has only one ethernet NIC , with ip 10.1.1.1  on it..
>
>Can you elaborate more on shared networks ?
>
>
>Regards
>    Alex
>
>
>----- Original Message ----- 
>From: "Randy Grimshaw" <rgrimsha at syr.edu>
>To: <dhcp-users at isc.org>
>Sent: Friday, November 10, 2006 5:29 AM
>Subject: Re: DHCPD , dhcp relays on a large network
>
>
>> alexandru:
>>   In your example the dhcp server does not need to be aware of the
>> vlans - that is being handled by your switches. Because they are acting
>> as bootp helpers right? It sounds like you need to review your
>> configuration for subnets. I suspect you may have more shared nets than
>> you realize.
>> <><Randy
>>
>>
>>
>> <><Randall Grimshaw
>> Room 203 Machinery Hall
>> Syracuse University
>> Syracuse, NY   13244
>> 315-443-5779
>> rgrimsha at syr.edu
>>>>> alexandru.coseru at totaltelecom.ro 11/09/06 5:55 PM >>>
>> Content-Type: text/plain;
>> charset="iso-8859-1"
>> Content-Transfer-Encoding: quoted-printable
>> Hello..
>>
>> I have a large network  with a couple of subnets and i want to configure
>> =
>> a DHCPD server  to lease IP addresses  to clients , connected through =
>> layer3 switches with relay agents on them.
>>
>>
>> Attached  is a small representation  (no of l3 switches reduced , to =
>> make it easier to understand).
>>
>>
>> On each switch I have some subnets , each one assigned to a specific =
>> VLAN.
>> Between switches , I'm running OSPF  , linked with quagga on srv1   =
>> (configured as ASBR) , which is also an internet router  (running bgpd =
>> with several ISPs).
>>
>>
>> Srv1:   has ip address 10.1.1.1 on VLAN 2.        The switches have IP =
>> 10.1.1.x  , on VLAN 2 also...   This VLAN is used for management and =
>> OSPF..
>> Each switch has an VLAN2 address  and a specific VLAN assigned to the =
>> clients subnet.      VLAN10,VLAN11 , VLAN12 , etc....
>>
>>
>> When I'm trying to declare all subnets in dhcpd.conf , i have the =
>> following error:    No subnet declaration for xxxxx.
>>
>> I cannot define aliases on the srv1 , cause it will break the internet =
>> routing...
>>
>> What should I do ?
>>
>> a) Install an separate server for DHCPD  and define eth0:1   =
>> 192.168.1.1/24 eth0:2 192.168.2.1/24 , etc  on it ?
>> b) Declare a subnet of  192.168.0.0/ 255.255.0.0  in dhcpd.conf ?
>>
>>
>> Thanks
>>    Alex
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> -- 
>> No virus found in this incoming message.
>> Checked by AVG Free Edition.
>> Version: 7.1.409 / Virus Database: 268.14.1/527 - Release Date: 11/9/2006
>>
>> 
>
>