none
A question about DHCP and VLAN. RRS feed

  • Question

  • Hello.

    I have a question about VLAN and DHCP. In a local network, each floor has its own IP range. For example, Floor 1 IP is 192.168.1.1-64 and Floor 2 is 192.168.1.65-128 and...

    DHCP configured something like below:

    Switch is Cisco and I want to know that for broadcast each IP range for each floor, Switch configured? I guess, Windows server broadcast these ranges via one NIC and this NIC plugged to switch and switch must configure for broadcast each range for specific floor.

    Thank you.

    Saturday, January 27, 2018 3:18 PM

All replies

  • Hi,


    For windows server(soft router)

    The DHCP Relay Agent component is a Bootstrap Protocol (BOOTP) relay agent that relays Dynamic Host Configuration Protocol (DHCP) messages between DHCP clients and DHCP servers on different IP networks. The DHCP Relay Agent is compliant with RFC 1542, "Clarifications and Extensions for the Bootstrap Protocol." For each IP network segment that contains DHCP clients, either a DHCP server or a computer acting as a DHCP Relay Agent is required.

    For switch

    Forward DHCP quest via IP helper.

    Since we are not familiar with Cisco, you could consult your vendor for better answer.


    Configure the IPv4 DHCP Relay Agent(Precondition :install RRAS role)

    https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2008-R2-and-2008/dd469685(v=ws.11)

     

    Best Regards,
    Frank

    Please remember to mark the replies as an answers if they help.
    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com



    Monday, January 29, 2018 3:04 AM
  • Hi,
    Just checking in to see if the information provided was helpful. Please let us know if you would like further assistance.

    Best Regards,

    Frank

    Please remember to mark the replies as an answers if they help.
    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com

    Thursday, February 1, 2018 8:39 AM
  • Hi,
    Just checking in to see if the information provided was helpful. Please let us know if you would like further assistance.

    Best Regards,

    Frank

    Please remember to mark the replies as an answers if they help.
    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com

    Thank you, But I just want to know switch do it for me(broadcast different IPs to each floor) or Windows Server do it? 
    Saturday, February 3, 2018 8:25 AM
  •  
    Hi,

    Remeber that a DHCP client broadcasts on the local link.  A relay agent receives the broadcast and transmits it to one or more DHCP servers using a unicast instead of a broad cast, thus being able to route the dhcp request to some other DHCP source that is not on the local network.  The relay agent stores its own IP address in the GIADDR field of the DHCP packet. The DHCP server uses the GIADDR to determine the subnet on which the relay agent received the broadcast, and allocates an IP address on that subnet. When the DHCP server replies to the client, it sends the reply to the GIADDR address, again using unicast. The relay agent then retransmits the response on the local network.



    Best Regards,
    Frank



    Please remember to mark the replies as an answers if they help.
    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com

    Monday, February 5, 2018 8:35 AM