ECS4100 Series CLI Reference Guide-R07

Chapter 32 | DHCP Commands
DHCP Relay
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DHCP Relay for IPv6
ipv6 dhcp relay
destination
This command specifies a DHCPv6 server or the VLAN to which client requests are
forwarded, and also enables DHCPv6 relay service on this interface. Use the no
form to disable this service.
Syntax
ipv6 dhcp relay destination {ipv6-address | multicast {all | vlan vlan-id}}
no ipv6 dhcp relay destination [ipv6-address | multicast {all |
vlan vlan-id}]
ipv6-address - A full IPv6 address including the network prefix and host
address bits. This address may designate another relay server or a DHCPv6
server.
multicast - All DHCP server multicast address (FF:05::1:3).
all - Specifies all local VLAN interfaces.
vlan-id - ID of configured VLAN. (Range: 1-4094)
Default Setting
None
Command Mode
Interface Configuration (VLAN)
Usage Guidelines
◆ You must specify the IPv6 address for at least one DHCPv6 server or another
relay agent, or the VLAN to which to multicast a relay message. Otherwise, the
switch’s DHCPv6 relay agent will not forward client requests. This command
enables DHCPv6 relay service for the VLAN from which the command is
entered.
◆ Up to five destination addresses may be defined using consecutive commands.
◆ This command is used to configure DHCPv6 relay functions for host devices
attached to the switch. If DHCPv6 relay service is enabled (by entering this
command), and this switch sees a DHCPv6 request broadcast, it inserts its own
IP address into the request so the DHCPv6 server will know the subnet where
the client is located. Then, the switch forwards the packet to the next relay
agent or DHCPv6 server on another network. When the server receives the
DHCPv6 request, it allocates a free IP address for the DHCPv6 client from its
defined scope for the DHCPv6 client’s subnet, and sends a DHCPv6 response
back to the DHCPv6 relay agent (i.e., this switch). This switch then broadcasts
the DHCPv6 response received from the server to the client.
◆ When the multicast option is used, the switch multicasts the modified client
request to all configured VLANs or to a specified VLAN, and enables DHCPv6
relay service for those VLANs.