DHCP snooping explained

In computer networking, DHCP snooping is a series of techniques applied to improve the security of a DHCP infrastructure.^[1]

DHCP servers allocate IP addresses to clients on a LAN. DHCP snooping can be configured on LAN switches to exclude rogue DHCP servers and remove malicious or malformed DHCP traffic. In addition, information on hosts which have successfully completed a DHCP transaction is accrued in a database of bindings which may then be used by other security or accounting features.^{[2] [3]}

Other features may use DHCP snooping database information to ensure IP integrity on a Layer 2 switched domain. This information enables a network to:

• Track the physical location of IP addresses when combined with AAA accounting or SNMP.
• Ensure that hosts only use the IP addresses assigned to them when combined with source-guard a.k.a. source-lockdown^[4]
• Sanitize ARP requests when combined with arp-inspection a.k.a. arp-protect

Notes and References

1. Web site: Banks. Ethan. Five Things To Know About DHCP Snooping. Packet Pushers. 29 February 2016.
2. Web site: What Is DHCP Snooping, all things you should know . Leslie . 22 March 2023.
3. Web site: DHCP Snooping . 14 July 2020 . Adarsh Sahni.
4. Web site: Cisco Systems, Inc. Catalyst 3750-X and Catalyst 3560-X Switch Software Configuration Guide, Cisco IOS Release 15.0(2)SE and Later. Cisco.com. 29 February 2016.