Chapter 24 IP Source Guard
GS3700/XGS3700 Series User’s Guide
225
The following table describes the labels in this screen.
24.5.2 DHCP Snooping VLAN Configure
Use this screen to enable DHCP snooping on each VLAN and to specify whether or not the Switch
adds DHCP relay agent option 82 information (
) to DHCP requests that the
Switch relays to a DHCP server for each VLAN. To open this screen, click Advanced Application >
IP Source Guard > DHCP Snooping > Configure > VLAN.
Figure 141
IP Source Guard > DHCP Snooping VLAN Configure
Table 109
IP Source Guard > DHCP Snooping Port Configure
LABEL
DESCRIPTION
Port
This field displays the port number. If you configure the * port, the settings are applied
to all of the ports.
Server Trusted state Select whether this port is a trusted port (Trusted) or an untrusted port (Untrusted).
Trusted ports are connected to DHCP servers or other switches, and the Switch discards
DHCP packets from trusted ports only if the rate at which DHCP packets arrive is too
high.
Untrusted ports are connected to subscribers, and the Switch discards DHCP packets
from untrusted ports in the following situations:
•
The packet is a DHCP server packet (for example, OFFER, ACK, or NACK).
•
The source MAC address and source IP address in the packet do not match any of
the current bindings.
•
The packet is a RELEASE or DECLINE packet, and the source MAC address and
source port do not match any of the current bindings.
•
The rate at which DHCP packets arrive is too high.
Rate (pps)
Specify the maximum number for DHCP packets (1-2048) that the Switch receives from
each port each second. The Switch discards any additional DHCP packets. Enter 0 to
disable this limit, which is recommended for trusted ports.
Apply
Click Apply to save your changes to the Switch’s run-time memory. The Switch loses
these changes if it is turned off or loses power, so use the Save link on the top
navigation panel to save your changes to the non-volatile memory when you are done
configuring.
Cancel
Click this to reset the values in this screen to their last-saved values.