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How Do I Serve DHCP Requests Received From a DNSMasq Relay Agent RRS feed

  • Question

  • Good-day folks,

    My network is comprised of two subnets - 172.23.6.0/24 [Lan-A] and 172.23.7.0/24 [Lan-B] located in so separate buildings.  The two buildings are connected via a fiber circuit and all traffic from Lan-B flows to Lan-A.  I have a Windows Server 2012 R2 located in Lan-A running DHCP for that network.  Up until today, I simply had a separate Linux box serving DHCP for Lan-B.  I would like to replace that box with DNSMasq in dhcp-relay-agent mode, to relay all the DHCP requests from Lan-B to the Windows Server on Lan-A.

    I have created a separate scope on the Windows Server and believe that I need to setup some kind of policy so that requests coming from Lan-B are served from that scope.  How do I accomplish this?

    Wednesday, June 22, 2016 2:06 AM

Answers

  • Thanks Anne,

    I think my question may have been misunderstood.  Wasn't looking for help on how to setup dnsmasq as a relay agent - already did that.  Was looking for how to configure the Windows Server to filter out the dhcp requests coming from the relay agent and assign IPs from the correct scope.

    But I came in this morning and it's working.  All i had to do was define a scope-specific policy using the MAC of the relay agent.  Address leases are being served from the appropriate scope now.  Thanks for the assist.

    Wednesday, June 22, 2016 10:39 AM

All replies

  • Hi Kismet-Gerald,

    Based on my understanding, you want to know how to configure DNSMasq to be a DHCP relay agent for DHCP server 2012 R2.

    Since DNSMasq is a third-party product, you may turn to DNSMasq forum for detailed information about how to configure it as DHCP relay agent. On DHCP server 2012 R2, we only need to create the related DHCP scope.

    As far DHCP packets, they are DHCPdiscover, DHCPoffer, DHCPrequest and DHCPack:

    Understanding relay agents

    https://technet.microsoft.com/en-sg/library/cc779610(v=ws.10).aspx

    Best Regards,

    Anne


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    Wednesday, June 22, 2016 8:36 AM
    Moderator
  • Thanks Anne,

    I think my question may have been misunderstood.  Wasn't looking for help on how to setup dnsmasq as a relay agent - already did that.  Was looking for how to configure the Windows Server to filter out the dhcp requests coming from the relay agent and assign IPs from the correct scope.

    But I came in this morning and it's working.  All i had to do was define a scope-specific policy using the MAC of the relay agent.  Address leases are being served from the appropriate scope now.  Thanks for the assist.

    Wednesday, June 22, 2016 10:39 AM