Alcatel-Lucent 7705 Service Manual page 374

IES Command Reference
dhcp
Syntax dhcp
Context config>service>ies>interface
Description This command enables the context to configure DHCP parameters.
option
Syntax [no] option
Context config>service>ies>interface>dhcp
Description This command enables DHCP Option 82 (Relay Agent Information Option) parameters processing
and enters the context for configuring Option 82 suboptions.
The no form of this command returns the system to the default.
Default no option
action
Syntax action {replace | drop | keep}
no action
Context config>service>ies>interface>dhcp>option
Description This command configures the Relay Agent Information Option (Option 82) processing.
The no form of this command returns the system to the default value.
Default keep
Parameters replace — in the upstream direction (from the user), the Option 82 field from the router is inserted in
drop — the DHCP packet is dropped if an Option 82 field is present, and a counter is incremented
keep — the existing information is kept in the packet and the router does not add any additional
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the packet (overwriting any existing Option 82 field). In the downstream direction (toward the
user), the Option 82 field is stripped (in accordance with RFC 3046).
information. In the downstream direction, the Option 82 field is not stripped and is forwarded
toward the client.
The behavior is slightly different in the case of Vendor Specific Options (VSOs). When the keep
parameter is specified, the router will insert its own VSO into the Option 82 field. This will only
be done if the incoming message already has an Option 82 field.
If no Option 82 field is present, the router will not create the Option 82 field. In this case, no VSO
will be added to the message.
7705 SAR OS Services Guide