H3C S7500 Series Ethernet Switches Operation Manual

Operation Manual – DHCP
H3C S7500 Series Ethernet Switches Chapter 4
DHCP Snooping Configuration
4-5
II. Enabling DHCP-Snooping option 82
Follow these steps to enable DHCP-snooping option 82 on a DHCP-snooping-enabled
network device:
To do… Use the command… Remarks
Enter system view
system-view
—
Enable DHCP-Snooping
option 82
dhcp-snooping
information enable
Required
This function is disabled
by default
4.3 Displaying and Maintaining DHCP Snooping
To do… Use the command… Remarks
Display the IP-MAC mappings
recorded by the
DHCP-Snooping-enabled switch
display dhcp-snooping
Display DHCP-Snooping status
and trusted port information
display dhcp-snooping trust
Display the total number of
DHCP-Snooping binding table
entries
display dhcp-snooping count
Display the DHCP-Snooping
binding table entries of the
specified VLAN
display dhcp-snooping vlan
{ vlan-list | all }
Available in
any view
Clear the IP-MAC mappings
recorded by the
DHCP-Snooping-enabled switch
reset dhcp-snooping
[ ip-address ]
Available in
user view
4.4 DHCP Snooping Configuration Example
I. Network requirements
As shown in Figure 4-3, the Ethernet 2/0/1 port of Switch A is connected to Switch B
(acting as a DHCP relay agent). A network segment containing some DHCP clients is
connect to the Ethernet 2/0/2 port of Switch A.
z The DHCP snooping function is enabled on Switch A.
z The DHCP-Snooping-enabled device supports option 82 and option 82 is enabled
on the switch.
z The Ethernet 2/0/1 port of Switch A is a trusted port.