Configuring DHCP

1 How Abiquo uses DHCP
2 DHCP server only, for < 200 VLANs.
3 DHCP server with DHCP relay, for < 1000 VLANs.
4 DHCP server with multiple DHCP relays, for > 1000 VLANs
5 DHCP configuration notes

This page describes the Abiquo DHCP configuration that uses a DHCP server with OMAPI.

If you are using NSX-T or NSX-V, Abiquo will use its DHCP server
For the DHCP service with dnsmasq, see https://abiquo.atlassian.net/wiki/spaces/ABI61/pages/652331632
The Abiquo Remote Services include a DHCP server that is configured to listen on VLANs. But to configure your own DHCP server, see https://abiquo.atlassian.net/wiki/spaces/ABI61/pages/652331503
If you have a datacenter without DHCP, you can configure VMs with https://abiquo.atlassian.net/wiki/spaces/ABI61/pages/652338463

For Abiquo private, external and public networks, the platform can manage the corresponding VLANs with an ISC DHCP server.

Abiquo recommends one DHCP server per physical datacenter. When you configure the datacenter, add the DHCP service to Abiquo.

If you have many virtual networks, you might need a separate relay server to manage VLANs for the DHCP server.
For unmanaged networks only, you do not need to configure a DHCP server and you must provide the network addresses to the VMs outside of Abiquo.

How Abiquo uses DHCP

Abiquo standard VLAN management has the following features:

Virtual networks as separate VLANs
The Cloud Administrator defines VLAN tag pools in Abiquo when creating the racks
External and public networks are created in the infrastructure and defined in Abiquo later
Private networks will be defined by Abiquo from the VLAN tag pools of the racks

The connections in DHCP are as follows:

When you deploy a VM, Abiquo (Remotes Services) supplies the network settings for the new VM to the DHCP Server.
When the new VM powers on, it broadcasts a DHCP request for network configuration.
The hypervisor passes the DHCP request through a VLAN to the DHCP server.
The DHCP server broadcasts a lease with the network configuration for the VM over the same VLAN

When configuring the DHCP infrastructure, there are several choices depending on the number of VLANs in the environment.

DHCP server only, for < 200 VLANs.

The Server listens to all VLANs. We recommend using a dedicated DHCP Server for this configuration.

DHCP server only

DHCP server with DHCP relay, for < 1000 VLANs.

The relay server listens on all the VLANs and forwards the DHCP requests to the Server.
In this configuration you can use the DHCP server on the Remote Services server. Do not configure support for VLANs on the DHCP Server.

DHCP server with DHCP relay

DHCP server with multiple DHCP relays, for > 1000 VLANs

Multiple DHCP relay servers allow you to create large networks in a hierarchical forwarding structure.

DHCP configuration notes

The server managing a VLAN (DHCP Relay or DHCP Server) must have one interface with IP in the VLAN that will identify the VLAN in the DHCP Server.

To configure a single DHCP server with VLAN support, see https://abiquo.atlassian.net/wiki/spaces/ABI61/pages/652331503 .

To install a DHCP Relay server with the Abiquo appliances see https://abiquo.atlassian.net/wiki/spaces/ABI61/pages/652331533 .

These configurations are designed for multiple VLAN networks, which by definition have separate VLAN tags and isolate DHCP broadcasts. The DHCP Server and VM communicate through broadcasts, which are also relayed, until the IP address of the VM is set, so there is no specific requirement for the IP address of the VNIC or NIC. However, it is recommended that the IP address range used for the VNICs or NICs is not part of any other networks. For example, you could use the upper range of the management network. If you have complex requirements, you may need to adapt these configurations.

If you need to use multiple relay servers, see https://abiquo.atlassian.net/wiki/spaces/ABI61/pages/652331569 .