DHCP snooping

In computer networking, DHCP snooping is a series of techniques applied to improve the security of a Dynamic Host Configuration Protocol (DHCP) infrastructure.^[1]

Techniques

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

References

↑ Banks, Ethan. "Five Things To Know About DHCP Snooping". Packet Pushers. Retrieved 29 February 2016.
↑ "What Is DHCP Snooping, all things you should know". Leslie. Retrieved 22 March 2023.
↑ "DHCP Snooping". Adarsh Sahni. 14 July 2020.
↑ 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. Retrieved 29 February 2016.

[Packet_Pushers-1] Banks, Ethan. "Five Things To Know About DHCP Snooping". Packet Pushers. Retrieved 29 February 2016.

[2] "What Is DHCP Snooping, all things you should know". Leslie. Retrieved 22 March 2023.

[3] "DHCP Snooping". Adarsh Sahni. 14 July 2020.

[4] 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. Retrieved 29 February 2016.

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Techniques

References