IP Configuration
IPv4 Management and Interfaces
Cisco 500 Series Stackable Managed Switch Administration Guide Release 1.3 304
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STEP 1 Enable DHCP Snooping and/or DHCP Relay in the IP Configuration > DHCP > 
Properties page or in the Security > DHCP Snooping > Properties page.
STEP  2 Define the interfaces on which DHCP Snooping is enabled in the IP Configuration 
> DHCP > Interface Settings page.
STEP  3 Configure interfaces as trusted or untrusted in the IP Configuration > DHCP > 
DHCP Snooping Interface page.
STEP  4 Optional. Add entries to the DHCP Snooping Binding database in the IP 
Configuration > DHCP > DHCP Snooping Binding Database page.
DHCP Snooping/Relay
This section describes how the DHCP Relay and Snooping features are 
implemented via the Web-based interface.
Properties
To configure DHCP Relay, DHCP Snooping and Option 82: 
STEP 1 Click IP Configuration > IPv4 Management and Interfaces > 
DHCP Snooping/Relay > Properties or Security > DHCP Snooping.
Enter the following fields:
• Option 82—Select Option 82 to insert Option 82 information into packets. 
• DHCP Relay—Select to enable DHCP Relay.
• DHCP Snooping Status—Select to enable DHCP Snooping. If DHCP 
Snooping is enabled, the following options can be enabled:
-
Option 82 Passthrough
—Select to leave foreign Option 82 information 
when forwarding packets.
-
Verify MAC Address
—Select to verify that the source MAC address of 
the Layer 2 header matches the client hardware address as appears in 
the DHCP Header (part of the payload) on DHCP untrusted ports.
-
Backup Database
—Select to back up the DHCP Snooping Binding 
database on the device’s flash memory.
-
Backup Database Update Interval
—Enter how often the DHCP Snooping 
Binding database is to be backed up (if Backup Database is selected).