A rogue DHCP server is a DHCP server installed on a network by an attacker but not under the network administrators' control. Rogue DHCP servers can cause severe problems for networks. Either a modem or a router might serve this purpose. Hackers usually utilize rogue DHCP servers to conduct network attacks such as sniffing, reconnaissance, and man-in-the-middle attacks. However, rogue DHCP servers can also be used for other purposes.