📖 What is Dynamic ARP Inspection (DAI)?
A security feature that validates ARP packets in a network by checking them against the DHCP snooping binding database and dropping packets with invalid IP-to-MAC bindings.
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Sensei Says:
"DAI requires DHCP Snooping to be enabled first (or static ARP ACLs for hosts not using DHCP), otherwise it drops all ARP packets on untrusted ports!"
📚 Certification: Certified Network Associate (200-301)
🔑 What are the Key Concepts of Dynamic ARP Inspection (DAI)?
- ▸ Validates ARP packets
- ▸ Relies on DHCP snooping binding database
- ▸ Mitigates ARP poisoning/spoofing
🎯 How does Dynamic ARP Inspection (DAI) appear on the 200-301 Exam?
Implementing DAI and realizing static IP hosts are losing connectivity until an ARP ACL is configured.
Identifying why valid ARP requests are dropped on an untrusted port.
❓ Frequently Asked Questions
What prerequisite must be met before enabling DAI?
DHCP Snooping must be enabled so that DAI can use the binding database, unless using static ARP ACLs.
How does DAI determine if an ARP packet is valid?
It checks the sender IP and MAC address in the ARP packet against the DHCP snooping binding database.
Related Terms from Certified Network Associate
Secure Shell (SSH)
Domain Name System (DNS)
JSON (JavaScript Object Notation)
Port Aggregation Protocol (PAgP)
NTP Stratum
Standard ACL