DHCP Lease Logs
networkPerimeter SecurityNetwork CaptureSIEM / Log Aggregator
Location
DHCP server logs (Windows DHCP Server, ISC DHCP dhcpd.leases, Infoblox)Description
DHCP lease transaction logs recording IP address assignments with MAC address, hostname, lease duration, and timestamps for DISCOVER, OFFER, REQUEST, and ACK messages.
Forensic Value
DHCP logs solve the critical problem of mapping IP addresses to physical devices at a specific point in time. When firewall or IDS logs show a suspicious internal IP, DHCP records identify the MAC address and hostname of the device that held that IP at the relevant timestamp. This is essential in environments with dynamic addressing. Historical leases also reveal rogue devices that connected to the network and obtained addresses.
Tools Required
SIEM (Splunk, Elastic)DHCP server consolegrepPowerShell (Get-DhcpServerv4Lease)