Users Guide

DHCPv6 Remote-ID Option (option 37)
The DHCPv6 remote-ID option (option 37) is used to specify the remote host identification in the RELAY-FORWARD packet to
the DHCPv6 server. This option is similar to the DHCPv4 relay option 82 sub option 2 remote-id. The remote-ID field contains
vendor specific enterprise-number and DHCPv6 relay agent DUID by default. The system uses 674 as the enterprise-number.
The DHCPv6 server uses this option to select parameters based on the DHCPv6 relay agent.
The remote identification is configured globally. By default, DHCPv6 relay agent type 3 DUID (system mac) is used as remote-ID
value. You can optionally configure a customized string to be used. In VLT cases, VLT MAC address is used to generate DUID.
The prefix is an optional parameter to be configured globally. You can configure hostname and VRF name or customized string
as prefix. Optionally, you can also configure DHCPv6 hostname.
The prefix and the remote identification are separated by the colon ( : ). For example, prefix : Remote Identification
Remote-ID (option 37) option is disabled by default in the DHCPv6 relay agent.
Restrictions and Limitations
If there is a mismatch in the interface-ID option between the VLT peers, the DHCPv6 client originated packet is dropped and a
log is created to indicate the interface-ID option mismatch.
If there is a mismatch in the remote-ID option between the VLT peers, the DHCPv6 client originated packet is dropped and a log
is created to indicate the remote-ID option mismatch.
If DHCPv6 hostname is configured for prefix, then Dell EMC Networking recommendeds to configure the same hostname for
both the VLT peers.
Parameter assignment based on Interface-ID option
The DHCPv6 server uses link addresses in the DHCPv6 RELAY-FORWARD packet to select the subnet from which the IPv6
address is assigned to the clients. If interface-ID option is enabled, then the interface-ID option in the RELAY-FORWARD packet
is used to select the subnet and other configuration parameters. The DHCPv6 server is configured with the policy to assign IPv6
address or configuration parameters based on the interface-ID.
In the following diagram, the Host1, Host2, and Host3 could get different set of DHCPv6 subnet and configuration parameters
based on the interface-ID option.
The interface description is a combination of VLAN and port information. By default, the interface name is used for the interface
description. The VLAN name and the port name are separated by a hyphen (-). You can optionally configure the customized
string for each interface using textual description configuration.
The prefix is an optional parameter to be configured globally. You can configure hostname, VRF Name, hostname, and VRF name
or customized string as prefix. Optionally, you can also configure DHCPv6 hostname. For example, Prefix:<VLAN name>-<Port
name>.
Following are the different formats of the interface-ID value with different configurations of the prefix.
Host name as prefix :
<Host name> : <VLANname>-<Portname>
e.g.: DELL OS10:vlan200-ethernet1/1/2
VRF Name as prefix :
294
System management