ZyXEL Communications MES-2110 manual 144, Dhcp requests will not succeed

Chapter 19 IP Source Guard

The following table describes the labels in this screen.

Table 53 Configuration > IP Source Guard > DHCP > DHCP Snooping Configuration

LABEL	DESCRIPTION
DHCP Snooping Configuration
Action	Select Enable to have the MES-2110 use DHCP snooping . You
	still have to enable DHCP snooping on specific VLAN and specify
	trusted ports.
	Select Disable if you do not want to use this feature.

	Note: If DHCP is enabled and there are no trusted ports,
	DHCP requests will not succeed.
DHCP snooping VLAN	Select All-VLANto have the Switch forward DHCP frames of any
Mode	VLANs to DHCP servers automatically.
	Select Fixed to have the Switch forward DHCP frames of a
	specific VLAN to DHCP servers.
DHCP Snooping	Select Enable to have the MES-2110 add DHCP relay agent
Option	option 82 information to DHCP requests that the MES-2110
	relays to a DHCP server for each VLAN. Otherwise, select
	Disable.
Option82 Information	Enter a unique identifier (such as the MES-2110’s MAC address)
	for the DHCP relay agent. This must be globally unique. You can
	enter up to 64 ASCII characters.
DHCP VLAN (Fixed)	Enter the ID of a static VLAN; the valid range is between 1 and
	4094.
Port	This field displays the port number. If you configure the * port,
	the settings are applied to all of the ports.
Trust	Use this to set trusted ports.
	Trusted ports are connected to DHCP servers or other switches,
	and the MES-2110 discards DHCP frames from trusted ports only
	if the rate at which DHCP frames arrive is too high.
Untrust	Use this to set un-trusted ports.
	Untrusted ports are connected to subscribers, and the MES-2110
	discards DHCP frames from untrusted ports in the following
	situations:
	• The frame is a DHCP server frame (for example, OFFER, ACK,
	or NACK).
	• The source MAC address and source IP address in the frame
	do not match any of the current bindings.
	• The frame is a RELEASE or DECLINE frame, and the source
	MAC address and source port do not match any of the current
	bindings.
	• The rate at which DHCP frames arrive is too high.
All Port	Use this to configure all ports as trusted or un-trusted ports.
Undo	Click this to reset the values in this screen to their last-saved
	values.

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MES-2110 User’s Guide