Applies To:Show Versions
BIG-IP Link Controller
Configuring the BIG-IP System as a DHCP Relay Agent
Overview: Managing IP addresses for DHCP clients
BIG-IP object type
BIG-IP pool member
A DHCP relay target (such as a DHCP server or BOOTP server). This is the dynamic address server to which the BIG-IP system forwards unicast requests.
BIG-IP virtual server
A BIG-IP system address on the listening VLAN
BIG-IP VLAN assigned to a virtual server
A listening VLAN, controlled on a per-virtual server basis
About the BIG-IP system as a DHCP relay agent
- You must configure the BIG-IP relay agent to relay the client DHCP requests to the DHCP servers without losing the originating subnet (source) IP address. This originating source IP address is typically a self IP address of the BIG-IP system that resides on the client subnet. You configure the BIG-IP relay agent to preserve the originating source IP address by creating a SNAT that specifies the originating self IP address as both the origin address and the translation address. A SNAT configured in this way prevents the BIG-IP relay agent, before sending the DHCP broadcast message to the DHCP servers, from translating the source IP address of the incoming DHCP request to a different address.
- You must add a route (to the BIG-IP relay agent) that specifies the originating source IP address as the destination for DHCP responses. The DHCP servers use this route to send their responses back through the BIG-IP relay agent to the clients.
for configuring system as a DHCP relay agent
Creating a DHCP type virtual server
- On the Main tab, click.The Virtual Server List screen opens.
- ClickCreate.The New Virtual Server screen opens.
- In theNamefield, type a unique name for the virtual server.
- Type a description for the virtual server.
- From theTypelist, selectDHCP.
- Select one of the following to configure aDestination Addresstype.DestinationSteps to configure255.255.255.255 (IPv4 Default)None.ff02::1:2 (IPv6 Default)None.OtherFor a host or network, in theDestination Addressfield, type an IPv4 address/prefix or an IPv6 address/prefix.
- From theStatelist, selectEnabled.
- In the Configuration area for theVLAN and Tunnel Trafficsetting, select the VLANs on the same network as the DHCP clients to ensure that the BIG-IP system can accept the broadcast traffic from the client.
- From theDefault Poollist, select the pool that is configured for DHCP servers.
Creating a pool of DHCP servers
- On the Main tab, click.The Pool List screen opens.
- ClickCreate.The New Pool screen opens.
- In theNamefield, type a unique name for the pool.
- Type a description for the pool.
- For theHealth Monitorssetting, in theAvailablelist, selectUDP, and click<<to move the monitor to theActivelist.
- From theLoad Balancing Methodlist, select a method.A DHCP pool requires a load balancing method, although actual load balancing across DHCP pool members is ignored and DHCP requests are sent to all DHCP pool members.
- For thePriority Group Activationsetting, selectDisabled.
- Add each resource that you want to include in the pool using theNew Memberssetting:
- Type a name in theNode Namefield, or select a node address from theNode List.
- Type an IP address in theAddressfield, or select a node address from theNode List.
- Type67(IPv4) or547(IPv6) in theService Portfield.