Defense in Depth: DHCP Snooping + DAI

Bundle lab · $29.99

Harden the Layer-2 access edge by deploying a unified trust boundary for DHCP Snooping and Dynamic ARP Inspection (DAI) on a single access switch. R1 is both the default gateway and DHCP server for VLAN 10. You will enable DHCP Snooping and DAI globally for VLAN 10 and set the same uplink interface as trusted for both features, leaving host-facing access ports untrusted. This lab emphasizes the dependency and synergy between DHCP Snooping and DAI for blocking rogue DHCP/ARP activity. Grade scope: SW1 config only.

Learning objectives

• Establish a single, consistent trust boundary for DHCP Snooping and DAI on an access switch
• Enable DHCP Snooping and DAI globally for a specific user VLAN
• Apply trust on the uplink while keeping access ports untrusted
• Verify feature state and alignment with show commands and basic reachability tests

Troubleshooting focus

• If ARP is being dropped, verify that ip dhcp snooping is enabled globally and for the correct VLAN
• Confirm the uplink to the DHCP server/gateway is trusted for BOTH snooping and DAI
• Ensure VLAN 10 exists and all access ports are in VLAN 10 so DHCP bindings, if generated, match the host ports
• Check that DAI is enabled for the same VLAN(s) as DHCP Snooping