ZyXEL Communications GS2200-24P Series, User Manual, Page: 241 / 360

Chapter 25 IP Source Guard
GS2200-24/24P User’s Guide
241
25.10 Technical Reference
This section provides technical background information on the topics discussed in
this chapter.
25.10.1 DHCP Snooping Overview
Use DHCP snooping to filter unauthorized DHCP packets on the network and to
build the binding table dynamically. This can prevent clients from getting IP
addresses from unauthorized DHCP servers.
25.10.1.1 Trusted vs. Untrusted Ports
Every port is either a trusted port or an untrusted port for DHCP snooping. This
setting is independent of the trusted/untrusted setting for ARP inspection. You can
also specify the maximum number for DHCP packets that each port (trusted or
untrusted) can receive each second.
VID This field displays the VLAN ID of each VLAN in the range specified
above. If you configure the * VLAN, the settings are applied to all
VLANs.
Enabled Select Yes to enable ARP inspection on the VLAN. Select No to disable
ARP inspection on the VLAN.
Log Specify when the Switch generates log messages for receiving ARP
packets from the VLAN.
None: The Switch does not generate any log messages when it
receives an ARP packet from the VLAN.
Deny: The Switch generates log messages when it discards an ARP
packet from the VLAN.
Permit: The Switch generates log messages when it forwards an ARP
packet from the VLAN.
All: The Switch generates log messages every time it receives an ARP
packet from the VLAN.
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.
Table 76 ARP Inspection VLAN Configure (continued)
LABEL DESCRIPTION