Dhcp Snooping Vlan Configuration; Dhcp Snooping Interface Configuration; Figure 102: Dhcp Snooping Vlan Configuration; Table 87: Dhcp Snooping Vlan Configuration - D-Link DWS-4026 User Manual

Software User Manual
12/10/09
DHCP S VLAN C
NOOPING
The DHCP snooping application does not forward server messages because they are forwarded in hardware.
DHCP snooping forwards valid DHCP client messages received on non-routing VLANs. The message is forwarded on all
trusted interfaces in the VLAN.
DHCP snooping can be configured on switching VLANs and routing VLANs. When a DHCP packet is received on a routing
VLAN, the DHCP snooping application applies its filtering rules and updates the bindings database. If a client message
passes filtering rules, the message is placed into the software forwarding path, where it may be processed by the DHCP
relay agent, the local DHCP server, or forwarded as an IP packet.
DHCP snooping is disabled globally and on all VLANs by default. Ports are untrusted by default.
To access the DHCP Snooping VLAN Configuration page, click LAN > L2 Features > DHCP Snooping > VLAN
Configuration in the navigation tree.
Field
VLAN ID
DHCP Snooping Mode
• Click Submit to apply the new configuration and cause the change to take effect. These changes will not be retained
across a power cycle unless a Save configuration is performed.
DHCP S I
NOOPING NTERFACE
The hardware rate limits DHCP packets sent to the CPU from untrusted interfaces to 15 packets per second. There is no
hardware rate limiting on trusted interfaces.
To prevent DHCP packets from being used as a DoS attack when DHCP snooping is enabled, the snooping application
enforces a rate limit for DHCP packets received on untrusted interfaces. DHCP snooping monitors the receive rate on each
interface separately. If the receive rate exceeds the configuration limit, DHCP snooping brings down the interface. You must
do "no shutdown" on this interface to further work with that port. You can configure both the rate and the burst interval.
Document 34CSFP6XXUWS-SWUM100-D7
ONFIGURATION

Figure 102: DHCP Snooping VLAN Configuration

Table 87: DHCP Snooping VLAN Configuration

Description
Select the VLAN for which information to be displayed or configured for the DHCP
snooping application.
Enables or disables the DHCP snooping feature on the selected VLAN. The default is
Disable.
C
ONFIGURATION
D-Link Unified Access System
Configuring DHCP Snooping Page 177