ZyXEL Communications IES-708-22A - Manual (Page 185)

IES-708-22A User’s Guide
185
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H A P T E R
27
DHCP Snoop
This feature is available in STU-C mode only.
This chapter shows you how to set up DHCP snooping settings on the subscriber ports.
27.1 DHCP Snoop Overview
DHCP snooping prevents clients from assigning their own IP addresses. The IES-708-22A can
store every (DSL port, MAC address, IP address) tuple offered by the DHCP server. Then, it
only forwards packets from clients whose MAC address and IP address are recorded. Packets
from unknown IP addresses are dropped.
27.2 DHCP Snoop Screen
Use this screen to activate or deactivate DHCP snooping on each port. To open this screen,
click Advanced Application > DHCP Snoop.
Figure 91 Advanced Application > DHCP Snoop
The following table describes the labels in this screen.
Table 57 Advanced Application > DHCP Snoop
LABEL DESCRIPTION
DHCP Snoop Status Click DHCP Snoop Status to open the screen where you can look at or clear
the current DHCP snooping table on each port (see Section 27.3 on page 186 ).
DHCP Counter Click DHCP Counter to open the screen where you can look at a summary of
the DHCP packets on each port (see Section 27.4 on page 187 ).
Port This field displays each DSL port number.
Active This field displays whether DHCP snooping is active (“V”) or inactive (“-”) on this
port.