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Setting up Windows 2012 R2 DHCP with multiple scopes & more than one VLAN RRS feed

  • Question

  • Hello,

    I have a Windows 2012 R2 server connected via a 10g fiber module to an Alcatel 6860 (on port 49).    I am connecting on our default VLAN fine and DHCP for our default VLAN is working fine.

    VLAN 10 - 10.100.170.x  default VLAN     DHCP scope 10.10.10.50-10.10.11-250
    VLAN 30 - 10.110.170.x  wireless VLAN (internal)  DHCP scope 10.10.100.50-10.10.101.250

    Server nic
    10.100.170.10
    255.255.254.0
    10.100.170.1


    Do I just add the second IP to that nic?   I tried that and I don't seem to be able to distribute DHCP

    IPCONFIG
    10.100.170.10
    255.255.254.0
    10.110.170.10
    255.255.254.0
    10.100.170.10


    From the switch - (connected to the server on port 49)
    -> show vlan members port 1/1/49
      vlan      type        status
    --------+-----------+---------------
        10    default     forwarding
        30    qtagged     forwarding
        40    qtagged     forwarding
        50    qtagged     forwarding


    • Edited by boe_d Wednesday, May 18, 2016 5:21 AM
    Wednesday, May 18, 2016 1:44 AM

Answers

  • Hi boe_d,

    Based on my understanding, you want to assign IP settings to clients in different VLANs.

    When DHCP server and DHCP clients in different subnets (VLANs), we need to use DHCP relay agent. And it is not recommended to make DHCP server multihomed or have multiples IP addresses.

    If you want to learn DHCP relay agent, you may click the following article:

    https://technet.microsoft.com/en-sg/library/cc779610%28v=ws.10%29.aspx?f=255&MSPPError=-2147217396

    Generally, routers have relay agent function, you may consult the routers provider to check if you can configure the router to be a DHCP relay agent, if you want to use windows servers to relay DHCP packets, then, you may configure on RRAS server.

    Best Regards,

    Anne


    Please remember to mark the replies as answers if they help and unmark them if they provide no help. If you have feedback for TechNet Support, contact tnmff@microsoft.com.


    Wednesday, May 18, 2016 7:50 AM
    Moderator

All replies

  • Hi boe_d,

    Based on my understanding, you want to assign IP settings to clients in different VLANs.

    When DHCP server and DHCP clients in different subnets (VLANs), we need to use DHCP relay agent. And it is not recommended to make DHCP server multihomed or have multiples IP addresses.

    If you want to learn DHCP relay agent, you may click the following article:

    https://technet.microsoft.com/en-sg/library/cc779610%28v=ws.10%29.aspx?f=255&MSPPError=-2147217396

    Generally, routers have relay agent function, you may consult the routers provider to check if you can configure the router to be a DHCP relay agent, if you want to use windows servers to relay DHCP packets, then, you may configure on RRAS server.

    Best Regards,

    Anne


    Please remember to mark the replies as answers if they help and unmark them if they provide no help. If you have feedback for TechNet Support, contact tnmff@microsoft.com.


    Wednesday, May 18, 2016 7:50 AM
    Moderator
  • Thanks - I'll look into this.
    Wednesday, May 18, 2016 1:03 PM
  • Thanks - I think everything is working - I'll know tomorrow.

    Unfortunately I did not get it working.   I posted details and a diagram here if anyone is more familiar with alcatel - http://www.alcatelunleashed.com/viewtopic.php?f=410&t=26128

    • Edited by boe_d Saturday, May 21, 2016 10:43 PM
    Thursday, May 19, 2016 2:00 AM
  • Do  you need more than one IP on the nic for multiple scope subnets or does one cover it if you have relay or rras?
    Sunday, May 22, 2016 9:16 PM
  • Hi boe_d,

    >Do  you need more than one IP on the nic for multiple scope subnets or does one cover it if you have relay or rras?

    DHCP server has one NIC with one IP address, DHCP relay agent has multiple NICs, each NIC has one IP address.

    For example, DHCP server's IP address is 192.168.1.5, on the DHCP sever has two scopes: 192.168.1.0/24(Subnet1) and 192.168.2.0/24(subnet2). Then for clients in subnet2, we need to set up relay agent. The relay agent needs two NICs (or more), one NIC's IP address need to be in subnet1(192.168.1.x), another NIC's IP address need to be in subnet2(192.168.2.x), in this way, DHCP relay agent can relay packets between DHCP server and clients in subnet2. For subnet2, DHCP packets between clients and DHCP relay agent are multicast, DHCP packets between DHCP relay agent and DHCP server are unicast. So, routers or RRAS server usually have multiple NICs, they need to combine different subnets.

    If my explanation is not clear, feel free to ask.

    Best Regards,

    Anne


    Please remember to mark the replies as answers if they help and unmark them if they provide no help. If you have feedback for TechNet Support, contact tnmff@microsoft.com.



    Monday, May 23, 2016 2:05 AM
    Moderator