CLI Reference Guide-R07

Chapter 26 | DHCP Commands (IPv4 and IPv6)
DHCP Relay (IPv4 and IPv6)
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The relay agent is enabled if the command show ipv6 dhcp relay destination
interface displays at least one entry for a configured VLAN. The relay agent is
disabled if the command displays no entries.
Example
This example configures the switch to enable DHCPv6 relay agent service for VLAN
200 and sets a unicast destination IPv6 address.
Console(config)#interface vlan 200
Console(config-if)#ipv6 dhcp relay destination 2001:0db8:85a3::8a2e:0370:7334
Console(config-if)#
ipv6 dhcp relay
destination multicast
This command will enable the DHCPv6 relay agent and forward DHCPv6 client
messages to a multicast address. Use the no form of the command to delete all
DHCPv6 relay agent multicast destinations or specify a single multicast destination
address to be removed.
Syntax
ipv6 dhcp relay destination multicast {all | vlan vlan-id}
no ipv6 dhcp relay destination multicast {all | vlan vlan-id}
all - all configured VLANs
vlan vlan-id (Range: 1-4094)
Default Setting
Disabled
Command Mode
Interface Configuration (VLAN)
Command Usage
Use this command if you do not know the Unicast destination address of the
DHCPv6 servers or other relay agents. This command will relay DHCPv6 client
messages to a DHCPv6 server or relay agent by forwarding the messages to the
multicast address ALL_DHCP_SERVERS (FF05::1:3).
The command can be entered by either configuring a specific VLAN or using the
“all” option to specify all configured VLANs on which the DHCPv6 client message
will be forwarded using the multicast address. Multiple specific VLANs can be
entered by repeating the command for each specific VLAN.
Once an entry is entered using this command, the switch will listen on UDP port
547 for DHCPv6 messages from DHCPv6 clients. It will forward the client messages
on all or specified VLANs using the multicast address as the destination.