ZyXEL Communications VES1724-56 - DHCP Snooping VLAN Configure

Chapter 26 IP Source Guard
VES1724-56 User’s Guide
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The following table describes the labels in this screen.
26.5.2 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 (Chapter 35 on page 311) 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 154 DHCP Snooping VLAN Configure
Table 114 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.