User`s guide

Chapter 37 DHCP
XS1920 Series User’s Guide
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37.6 DHCPv6 Relay
A DHCPv6 relay agent is on the same network as the DHCPv6 clients and helps forward messages
between the DHCPv6 server and clients. When a client cannot use its link-local address and a well-
known multicast address to locate a DHCPv6 server on its network, it then needs a DHCPv6 relay
agent to send a message to a DHCPv6 server that is not attached to the same network.
The DHCPv6 relay agent can add the remote identification (remote-ID) option and the interface-ID
option to the Relay-Forward DHCPv6 messages. The remote-ID option carries a user-defined string,
such as the system name. The interface-ID option provides slot number, port information and the
VLAN ID to the DHCPv6 server. The remote-ID option (if any) is stripped from the Relay-Reply
messages before the relay agent sends the packets to the clients. The DHCPv6 server copies the
interface-ID option from the Relay-Forward message into the Relay-Reply message and sends it to
the relay agent. The interface-ID should not change even after the relay agent restarts.
Use this screen to configure DHCPv6 relay settings for a specific VLAN on the Switch. Click IP
Application > DHCP > DHCPv6 in the navigation panel to display the screen as shown.
Figure 222 IP Application > DHCP > DHCPv6
The following table describes the labels in this screen.
Table 159 IP Application > DHCP > DHCPv6
LABEL DESCRIPTION
VID Enter the ID number of the VLAN you want to configure here.
Helper Address Enter the remote DHCPv6 server address for the specified VLAN.
Options
Interface ID Select this option to have the Switch add the interface-ID option in the DHCPv6 requests
from the clients in the specified VLAN before the Switch forwards them to a DHCPv6 server.
Remote ID Enter a string of up to 64 printable characters to be carried in the remote-ID option. The
Switch adds the remote-ID option in the DHCPv6 requests from the clients in the specified
VLAN before the Switch forwards them to a DHCPv6 server.