Terminology » Networking Basics » TELNET vs DHCP: Key Differences & Port Numbers

TELNET vs DHCP: Key Differences & Port Numbers

telnet dhcp network protocol port number ip address

TELNET and DHCP are fundamentally different protocols serving distinct purposes within a network.

Telnet offers remote command-line access, but its major drawback is its lack of security, as it transmits data in plain text. DHCP, or Dynamic Host Configuration Protocol, automates IP address assignment, streamlining network administration and minimizing errors.

The following table highlights the key differences between Telnet and DHCP, including their respective port numbers:

Parameter	Telnet	DHCP
Functionality	Provides terminal access and control to a remote device or computer	Facilitates automatic IP address allocation and network configuration
Security	Insecure: data transmitted in clear text, susceptible to interception	Not inherently a security protocol. Secure versions like DHCPv6 exist.
Protocol Type	Application layer protocol	Network layer protocol
Communication	Full duplex communication between client and server	One-way communication from server to client
Port Number	23	Server: 67, Client: 68
Data Transmission	Commands and data sent in clear text	Network configuration details provided
Usage	Remote management of devices and systems; often replaced by SSH for security	Widely used in modern networks to simplify IP address assignment and network configuration
Direct Interaction	Allows direct user access and control of a remote device	Does not directly interact with Telnet
Network Discovery	Clients typically need to know the IP address of the Telnet server beforehand	Utilizes broadcast messages for clients to discover available DHCP servers
Common Alternatives	SSH (Secure Shell)	Static IP addressing or manual IP address configuration if DHCP is unavailable

While Telnet and DHCP are distinct protocols, they can coexist within a network environment. DHCP assigns IP addresses to devices, and administrators can then utilize Telnet (or more secure alternatives like SSH) for remote management. Due to security concerns, modern systems generally favor more secure remote access methods like SSH (Secure Shell) over Telnet.