ZyXEL Communications XS1920 Series, Руководство пользователя

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Chapter 26 IP Source Guard
XS1920 Series User’s Guide
229
Figure 153
Advanced Application > IP Source Guard > IPv4 Source Guard Setup > DHCP Snooping
> Configure
The following table describes the labels in this screen.
Table 104
Advanced Application > IP Source Guard > IPv4 Source Guard Setup > 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: If DHCP is enabled and there are no trusted ports, DHCP requests will not
succeed.
DHCP Vlan Select 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
( Section 26.5.3 on page 231 ) to help the DHCP servers distinguish between DHCP
requests from different VLAN.
Select Disable if you do not want the Switch to forward DHCP packets to a specific
VLAN.
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 interval Enter how long (10-65535 seconds) the Switch waits to update the DHCP snooping
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.