ZyXEL Communications MES3500-24S User Manual page 245

Figure 143 Advanced Application > IP Source Guard > DHCP Snooping Configure
The following table describes the labels in this screen.
Table 108 Advanced Application > IP Source Guard > DHCP Snooping Configure
LABEL DESCRIPTION
Active Select this to enable DHCP snooping on the Switch. You still have to enable DHCP snooping
on specific VLAN and specify trusted ports.
Note: The Switch will drop all DHCP requests if you enable DHCP snooping and
DHCP Vlan Select Disable if you do not want the Switch to forward DHCP packets to a specific VLAN.
Select the second option and specify a VLAN ID if you want the Switch to forward DHCP
packets to DHCP servers on a specific VLAN.
Note: You have to enable DHCP snooping on the DHCP VLAN too.
You can enable Option82 in the DHCP Snooping VLAN Configure screen
page
Database If Timeout interval is greater than Write delay interval, it is possible that the next update is
scheduled to occur before the current update has finished successfully or timed out. In this
case, the Switch waits to start the next update until it completes the current one.
Agent URL Enter the location of the DHCP snooping database. The location should be expressed like
this: tftp://{domain name or IP address}/directory, if applicable/file name; for example,
tftp://192.168.10.1/database.txt.
Timeout interval Enter how long (10-65535 seconds) the Switch tries to complete a specific update in the
DHCP snooping database before it gives up.
Write delay Enter how long (10-65535 seconds) the Switch waits to update the DHCP snooping
interval
database the first time the current bindings change after an update. Once the next
update is scheduled, additional changes in current bindings are automatically included in
the next update.
Chapter 27 IP Source Guard
there are no trusted ports.
247) to help the DHCP servers distinguish between DHCP requests from different VLAN.
MES3500-24S/MGS3520 Series User's Guide
245
(Section 27.5.2 on