The Un-Official CCNA guide #3: Differences and Similarities between Dynamic ARP Inspection and DHCP Snooping

Dynamic ARP Inspection and DHCP Snooping are often mixed up. Let’s discuss their differences and similarities/relationship between each other.

Differences:

Similarities:

1. Both DAI and DHCP Snooping involves trusted and untrusted ports. In general, trusted ports are ports connected to end hosts while untrusted ports are ports connected to other network devices.
2. Both DAI and DHCP Snooping are applied on a VLAN.

Relationship between DAI and DHCP Snooping:

1. DHCP Snooping binding table maps MAC addresses to IP addresses that are assigned via DHCP. DAI uses the table to ensure that ARP messages are genuine (IP address is indeed assigned to the MAC address). At the same time, DHCP Snooping enables DHCP snooping binding table to exist.