HP 2610, Advanced Traffic Management Manual

Page: 288 / 364

IP Routing Features
Configuring DHCP Relay
DHCP Policy Boundary: For Option 82 applications, an area of a network
as defined by connection to a given routing switch or subnet and/or a
specific port belonging to the routing switch or subnet.
DHCP relay agent: See Relay Agent.
Forwarding Policy: The Option 82 method the routing switch uses to process
incoming client DHCP requests. For a given inbound DHCP client request,
the forwarding policy determines whether the routing switch will add
Option 82 information, replace existing Option 82 information, or leave
any existing information unchanged. The policy also determines whether
the routing switch will forward the client request toward a DHCP server
or drop the request. For a DHCP server response to an Option 82 client
request, the routing switch can optionally perform a validation check to
determine whether to forward or drop the response. Each Option 82 relay
agent in the path between a DHCP client and an Option 82 DHCP server
can be configured with a unique forwarding policy, which enhances DHCP
policy control over discrete areas of a network.
Primary Relay Agent: In the path between a DHCP client and a DHCP server,
the first routing switch (configured to support DHCP operation) that a
client DHCP request encounters in the path from the client to a DHCP
server.
Relay Agent: A routing switch that is configured to support DHCP operation.
Remote ID: In Option 82 applications on ProCurve switches, either the MAC
address of a relay agent, or the IP address of a VLAN or subnet configured
on a relay agent. This value is included as a suboption in an Option 82 field
that the relay agent appends to a Client DHCP request before forwarding
the request toward a DHCP server. (For more on Remote ID, refer to
“Remote ID” in the bulleted list on page <zBlue>32.)
Secondary Relay Agent: In the path between a DHCP client and a DHCP
server, any routing switch (configured to support DHCP operation) other
than the primary relay agent.
General DHCP Option 82 Requirements and Operation
Requirements. DHCP Option 82 operation can be configured at the global
config level and requires the following:
■ IP routing enabled on the switch
■ DHCP-Relay Option 82 enabled (global command level)
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