Cisco 350XG series, Administration Manual

Page: 338 / 625

IP Configuration
IPv4 Management and Interfaces
Cisco 350XG & 550XG Series 10G Stackable Managed Switches 327
16
STEP 1
Click IP Configuration > IPv4 Management and Interfaces > DHCP Snooping/
Relay > Interface Settings.
STEP 2
To enable DHCP Relay or DHCP Snooping on an interface, click ADD .
STEP 3
Select the interface and the features to be enabled: DHCP Relay or DHCP
Snooping or both.
STEP 4
Click Apply. The settings are written to the Running Configuration file.
DHCP Snooping Trusted Interfaces
Packets from untrusted ports/LAGs are checked against the DHCP Snooping
Binding database (see the
DHCP Snooping Binding Database page).
By default, interfaces are trusted.
To designate an interface as untrusted:
STEP 1
Click IP Configuration > IPv4 Management and Interfaces > DHCP Snooping/
Relay > DHCP Snooping Trusted Interfaces.
STEP 2
Select the interface and click Edit .
STEP 3
Select Trusted Interface (Yes or No).
STEP 4
Click Apply to save the settings to the Running Configuration file.
DHCP Snooping Binding Database
See How the DHCP Snooping Binding Database is Built for a description of how
dynamic entries are added to the DHCP Snooping Binding database.
Note the following points about maintenance of the DHCP Snooping Binding
database:
• The device does not update the DHCP Snooping Binding database when a
station moves to another interface.
• If a port is down, the entries for that port are not deleted.
• When DHCP Snooping is disabled for a VLAN, the binding entries that were
collected for that VLAN are removed.