Chapter 25 IP Source Guard
GS2200-24 User’s Guide
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read. If the calculated checksum is not equal to the checksum in the file, that
binding and all others after it are ignored.
25.10.1.3 DHCP Relay Option 82 Information
The Switch can add information to DHCP requests that it does not discard. This
provides the DHCP server more information about the source of the requests. The
Switch can add the following information:
• Slot ID (1 byte), port ID (1 byte), and source VLAN ID (2 bytes)
• System name (up to 32 bytes)
This information is stored in an Agent Information field in the option 82 field of the
DHCP headers of client DHCP request frames. See
for
more information about DHCP relay option 82.
When the DHCP server responds, the Switch removes the information in the Agent
Information field before forwarding the response to the original source.
You can configure this setting for each source VLAN. This setting is independent of
the DHCP relay settings (
25.10.1.4 Configuring DHCP Snooping
Follow these steps to configure DHCP snooping on the Switch.
1
Enable DHCP snooping on the Switch.
2
Enable DHCP snooping on each VLAN, and configure DHCP relay option 82.
3
Configure trusted and untrusted ports, and specify the maximum number of DHCP
packets that each port can receive per second.
4
Configure static bindings.
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