Chapter 74 DHCP Snooping
XGS2220 Series User’s Guide
497
Figure 364
SECURITY > IPv4 Source Guard > DHCP Snooping > DHCP Snp. VLAN Port Setup > Add/Edit
The following table describes the labels in this screen.
74.7 Technical Reference
This section provides technical background information on the topics discussed in this chapter.
74.7.1 DHCP Snooping Overview
Use DHCP snooping to filter unauthorized DHCP packets on the network and to build the binding table
dynamically. This can prevent clients from getting IP addresses from unauthorized DHCP servers.
74.7.1.1 Trusted vs. Untrusted Ports
Every port is either a trusted port or an untrusted port for DHCP snooping. This setting is independent of
the trusted or untrusted setting for ARP inspection. You can also specify the maximum number for DHCP
packets that each port (trusted or untrusted) can receive each second.
Table 285 SECURITY > IPv4 Source Guard > DHCP Snooping > DHCP Snp. VLAN Port Setup > Add/Edit
LABEL
DESCRIPTION
VID
Enter the ID number of the VLAN you want to configure here.
Port
Enter the number of ports to which you want to apply the specified DHCP option 82 profile.
You can enter multiple ports separated by (no space) comma (,) or hyphen (-) for a range.
For example, enter “3-5” for ports 3, 4, and 5. Enter “3,5,7” for ports 3, 5, and 7.
Option 82 Profile
Select a pre-defined DHCP option 82 profile that the Switch applies to the specified ports in
this VLAN. The Switch adds the information (such as slot number, port number, VLAN ID and/
or system name) specified in the profile to DHCP requests that it broadcasts to the DHCP
VLAN, if specified, or VLAN. You can specify the DHCP VLAN in the
SECURITY
>
IPv4 Source
Guard
>
DHCP Snooping
>
DHCP Snp. Setup
screen.
Note: The profile you select here has priority over the one you select in the
SECURITY
>
IPv4 Source Guard
>
DHCP Snooping
>
DHCP Snp. VLAN Setup
screen.
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.
Clear
Click
Clear
to clear the fields to the factory defaults.
Cancel
Click
Cancel
to not save the configuration you make and return to the last screen.