C
HAPTER
16
| IP Services
Dynamic Host Configuration Protocol
– 599 –
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A DHCP relay server has been set on the switch, when the switch
receives a DHCP request packet with a non-zero relay agent
address field (that is not the address of this switch).
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A DHCP relay server has been set on the switch, when the switch
receives DHCP reply packet without option 82 information from the
management VLAN.
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The reply packet contains a valid relay agent address field (that is
not the address of this switch), or receives a reply packet with a
zero relay agent address through the management VLAN.
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A DHCP relay server has been set on the switch, and the switch
receives a reply packet on a non-management VLAN.
PARAMETERS
These parameters are displayed:
◆ Insertion of Relay Information – Enable DHCP Option 82
information relay. (Default: Disabled)
◆ DHCP Option Policy – Specifies how to handle client requests which
already contain DHCP Option 82 information:
Drop - Floods the original request packet onto the VLAN that
received it instead of relaying it. (This is the default.)
Keep - Retains the Option 82 information in the client request,
inserts the relay agent’s address, and unicasts the packet to the
DHCP server.
Replace - Replaces the Option 82 information circuit-id and
remote-id fields in the client’s request with information provided by
the relay agent itself, inserts the relay agent’s address, and unicasts
the packet to the DHCP server.
◆ DHCP Sub-option Format – Specifies whether or not to use the
sub-type and sub-length fields in the circuit-ID (CID) and remote-ID
(RID) in Option 82 information. (Default: Included)
◆ DHCP Remote ID Sub-option – Specifies the format used to identify
this switch as the DHCP relay agent to the DHCP server:
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MAC Address - Includes a MAC address field for the relay agent
(that is, the MAC address of the switch’s CPU). This attribute can be
encoded in hexadecimal or ASCII.
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IP Address - Includes the IP address field for the relay agent (that
is, the IP address of the management interface). This attribute can
be encoded in hexadecimal or ASCII.
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String - An arbitrary string inserted into the remote identifier field.
(Range: 1-32 characters)