To Next Page

To Previous Page

11-8

Configuring Advanced Threat Protection

DHCP Snooping

Figure 11-5. Example of Authorized Servers for DHCP Snooping

Using DHCP Snooping with Option 82

DHCP adds Option 82 (relay information option) to DHCP request packets

received on untrusted ports by default. (See “Configuring DHCP Relay” in the

Management and Configuration Guide for more information on Option 82.)

When DHCP is enabled globally and also enabled on a VLAN, and the switch

is acting as a DHCP relay, the settings for the DHCP relay Option 82 command

are ignored when snooping is controlling Option 82 insertion. Option 82

inserted in this manner allows the association of the client’s lease with the

correct port, even when another device is acting as a DHCP relay or when the

server is on the same subnet as the client.

Note DHCP snooping only overrides the Option 82 settings on a VLAN that has

snooping enabled, not on VLANS without snooping enabled.

HP Switch(config)# show dhcp-snooping

DHCP Snooping Information

DHCP Snooping : Yes

Enabled Vlans : 4

Verify MAC : No

Option 82 untrusted policy : drop

Option 82 Insertion : Yes

Option 82 remote-id : subnet-ip

Authorized Servers

---------------------

111.222.3.4

100011

HP J9574A Access Security Guide

Other manuals for HP J9574A