11-19
Configuring Advanced Threat Protection
Dynamic ARP Protection
Figure 11-9. Configuring Trusted Ports for Dynamic ARP Protection
Take into account the following configuration guidelines when you use 
dynamic ARP protection in your network:
■ You should configure ports connected to other switches in the network 
as trusted ports. In this way, all network switches can exchange ARP 
packets and update their ARP caches with valid information.
■ Switches that do not support dynamic ARP protection should be sepa-
rated by a router in their own Layer 2 domain. Because ARP packets do 
not cross Layer 2 domains, the unprotected switches cannot unknowingly 
accept ARP packets from an attacker and forward them to protected 
switches through trusted ports.
To configure one or more Ethernet interfaces that handle VLAN traffic as 
trusted ports, enter the arp-protect trust command at the global configuration 
level. The switch does not check ARP requests and responses received on a 
trusted port. 
An example of the arp-protect trust command is shown here:
HP Switch(config)# arp-protect trust b1-b4, d1
Syntax: [no] arp-protect trust <port-list>
port-list Specifies a port number or a range of port 
numbers. Separate individual port numbers or 
ranges of port numbers with a comma; for 
example: c1-c3, c6.