DHCP C
OMMANDS
37-6
the reply packet was received. If the DHCP packet’s broadcast
flag is off, the switch uses the Option 82 information to identify
the interface connected to the requesting client and unicasts the
reply packet to the client.
• DHCP reply packets are flooded onto all attached VLANs other
than the inbound management VLAN under the following situations
:
- The reply packet does not contain Option 8 2 information.
- The reply packet contains a valid relay agent address field (that is
not the address of this switch) or a zero relay address.
•Use the ip dhcp information policy command (page37-6) to
specify how to handle DHCP client request packets which already
contain Option 82 information.
Example
This example enables Option 82, and sets the frame format for the option
to use a circuit identifier.
Related Commands
ip dhcp information policy (37-6)
ip dhcp relay server (37-3)
ip dhcp snooping (23-18)
ip dhcp information policy
This command specifies how to handle client requests which already
contain DHCP Option 82 information.
Syntax
ip dhcp information policy {drop | keep | replace}
•drop - Drop the request packet instead of relaying it.
•keep - Retain the Option 82 information in the client request, insert
the relay agent’s address (when DHCP snooping or relay is enabled),
and unicast the packet to the DHCP server.
•replace - Replace the Option 82 information in the client’s request
with information about the relay agent itself, insert the relay agent’s
Console(config)#ip dhcp information option circuit-id
Console(config)#