New Feature Manual - DHCP 
Quidway S3900 Series Ethernet Switches-Release 1510 
Chapter 3  DHCP Snooping Configuratio
n Commands
 
Huawei Technologies Proprietary 
3-2 
View 
Ethernet port view 
Parameter 
None 
Description 
Use the dhcp-snooping trust command to set an Ethernet port to a trusted port. 
Use the undo dhcp-snooping trust command to restore an Ethernet port to an 
untrusted port. 
DHCP snooping security allow you to set a port to a trusted port or an untrusted port, 
so that DHCP clients can obtain IP addresses from only valid DHCP servers. 
z  Trusted ports can be used to connect DHCP servers or ports of other switches. 
Untrusted ports can be used to connect DHCP clients or networks. 
z  Trusted ports forward any received DHCP packets to ensure that DHCP clients 
can obtain IP addresses from valid DHCP servers. Untrusted ports discard the 
DHCP-ACK and DHCP-OFF responses received from DHCP servers. 
z  By default, all the ports of a switch are untrusted ports. 
Related command: display dhcp-snooping trust. 
Example 
# Enter system view. 
<Quidway> system-view 
System View: return to User View with Ctrl+Z. 
# Set the Ethernet1/0/1 port to a trusted port. 
[Quidway] interface Ethernet 1/0/1 
[Quidway-Ethernet1/0/1] dhcp-snooping trust 
3.1.3  display dhcp-snooping 
Syntax 
display dhcp-snooping [ unit unit-id ] 
View 
Any view 
Parameter 
unit unit-id: Displays the DHCP-snooping information on other devices in fabric when 
the switch is in fabric. unit-id indicates the number of the device whose 
DHCP-snooping information needs to be viewed.