DHCP snooping support for Option 82
Option 82 records the location information about the DHCP client so the administrator can locate the DHCP client for security and accounting purposes. For more information about Option 82, see "Relay agent option (Option 82)."
DHCP snooping uses the same strategies as the DHCP relay agent to handle Option 82 for DHCP request messages, as shown in Table 5. If a response returned by the DHCP server contains Option 82, DHCP snooping removes Option 82 before forwarding the response to the client. If the response contains no Option 82, DHCP snooping forwards it directly.
Table 5: Handling strategies
If a DHCP request has… | Handling strategy | DHCP snooping… |
|---|---|---|
Option 82 | Drop | Drops the message. |
Keep | Forwards the message without changing Option 82. | |
Replace | Forwards the message after replacing the original Option 82 with the Option 82 padded according to the configured padding format, padding content, and code type. | |
No Option 82 | N/A | Forwards the message after adding the Option 82 padded according to the configured padding format, padding content, and code type. |