Port 67

Q: What is port 67?

Automatic IP address assignment — DHCP server port The DHCP server listens on UDP port 67. When a device joins a network, it broadcasts a DHCP Discover packet to port 67; the server responds with an IP address, subnet mask, gateway, and DNS server configuration. The client receives these settings on UDP port 68. A rogue DHCP server on the network can intercept traffic (man-in-the-middle attack). Enterprise switches use DHCP snooping to prevent unauthorized DHCP servers.

DHCP

Automatic IP address assignment — DHCP server port

Port

Protocol

UDP

Service

DHCP

Security

Restricted

Full name: Dynamic Host Configuration Protocol – Server

What is port 67?

The DHCP server listens on UDP port 67. When a device joins a network, it broadcasts a DHCP Discover packet to port 67; the server responds with an IP address, subnet mask, gateway, and DNS server configuration. The client receives these settings on UDP port 68. A rogue DHCP server on the network can intercept traffic (man-in-the-middle attack). Enterprise switches use DHCP snooping to prevent unauthorized DHCP servers.

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