ZyXEL ES-4124 Manual Do Utilizador

Chapter 24 IP Source Guard

ES-4124 User’s Guide

Figure 104   DHCP Snooping Port Configure

The following table describes the labels in this screen.

Table 73   DHCP Snooping Port Configure

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.