3com WX3000 User Manual

 

2-7 

Set the interval at which the 
DHCP relay agent dynamically 
updates the client address 
entries 

dhcp-security tracker 
{ interval | auto } 

Optional 

By default, auto is adopted, that 
is, the interval is automatically 
calculated. 

 

If there is an unauthorized DHCP server in the network, when a client applies for an IP address, the 

unauthorized DHCP server may assign an incorrect IP address to the DHCP client.  

With this feature enabled, upon receiving a DHCP message with the siaddr field (IP addresses of the 

servers offering IP addresses to the client) not being 0 from a client, the DHCP relay agent will record 

the value of the siaddr field and the receiving interface. The administrator can use this information to 

check out any DHCP unauthorized servers. 

Follow these steps to enable unauthorized DHCP server detection: 

Enter system view 

— 

Enable unauthorized DHCP server 
detection  

Required 

Disabled by default. 

 

With the unauthorized DHCP server detection enabled, the relay agent will log all DHCP servers, 

including authorized ones, and each server is recorded only once until such information is removed and 

is recorded again. The administrator needs to find unauthorized DHCP servers from the system log 

information.  

 

Before configuring Option 82 support on a DHCP relay agent, you need to: 

z 

Configure network parameters and relay function of the DHCP relay device. 

z 

Perform assignment strategy-related configurations, such as network parameters of the DHCP 

server, address pool, and lease time. 

z 

The routes between the DHCP relay agent and the DHCP server are reachable. 

Follow these steps to configure the DHCP relay agent to support Option 82: