You can configure DHCP service on each segment regardless of whether the segment is connected to a gateway. Both DHCP for IPv4 (DHCPv4) and DHCP for IPv6 (DHCPv6) servers are supported.

NSX-T Data Center supports the following types of DHCP configuration on a segment:
  • Local DHCP server
  • Gateway DHCP server (supported only for IPv4 subnets in a segment)
  • DHCP Relay

High-level Overview of Configuration

The following figure shows the high-level overview of DHCP server configuration in NSX-T.


High level overview of DHCP server configuration in NSX-T Data Center.

The following figure shows the high-level overview of DHCP Relay configuration in NSX-T.


High level overview of DHCP Relay configuration in NSX-T Data Center.

Supported DHCP Configuration Types

The following figure shows an example of the various scenarios for Local DHCP server, Gateway DHCP server, and DHCP Relay in an NSX-T network.


Scenarios for DHCP Configuration Types in NSX-T Data Center.
Table 1. Types of DHCP Configuration in NSX-T
DHCP Configuration Type Description

Local DHCP server

Select this option to create a Local DHCP server that has an IP address on the segment. A Local DHCP server provides a dynamic IP assignment service only to the VMs that are attached to the segment. The DHCP server IP address must belong to the subnet that is configured on the segment. Also, the server IP address must be different from the Gateway IP address of the segment.

Local DHCP server is local to the segment and not available to the other segments in the network.

You can configure all DHCP settings, including DHCP ranges, DHCP Options, and static bindings on the segment.

For isolated segments, which are not connected to a gateway, Local DHCP server configuration type is selected by default.

You can configure DHCPv6 in the IPv6 subnet of a segment with a Local DHCP server.

DHCP Relay

Select this option to relay the DHCP client requests to the external DHCP servers. The external DHCP servers can be in any subnet, outside the SDDC, or in the physical network.

DHCP Relay service is local to the segment and is not available to the other segments in the network.

When you use a DHCP Relay on a segment, you cannot configure DHCP Settings and DHCP Options. The UI does not prevent you from configuring DHCP static bindings on the segment. However, in NSX-T Data Center, static binding with a DHCP Relay is an unsupported configuration.

Gateway DHCP server

Gateway DHCP server is analogous to a central DHCP server that dynamically assigns IP and other network configuration to the VMs on all the segments that are connected to the gateway and using Gateway DHCP server.

By default, segments that are connected to a tier-1 or tier-0 gateway use Gateway DHCP server. If needed, you can choose to configure a Local DHCP server or a DHCP Relay on the segment.

To configure Gateway DHCP server on a segment, a DHCP server profile must be attached to the gateway.

If the IPv4 subnet of a segment uses a Gateway DHCP server, you cannot configure DHCPv6 in the IPv6 subnet of the same segment because Gateway DHCPv6 server is not supported. In this case, the IPv6 subnet cannot support any DHCPv6 server configuration, including the IPv6 static bindings.