Rogue DHCP fix

DHCP (Dynamic Host Configuration Protocol) when a device is connected to a network, it shouts for an IP address. the DHCP server answers with an unused IP address, default gateway and DNS servers. Ideally.

Problems happen when someone non-technical plugs in a wireless gateway and it responds with IPs and DGW that DON’T get to the internet, or allow someone to spy on your internet traffic.

Solution: Managed switches have a function called DHCP Snooping. The switch looks for DHCP offers and drops those packets. The network manager can exempt upstream physical ports or IP addresses.

Example from HP 1920 series edge switch