DHCP Port Number | What is Port number of DHCP protocol
This page mentions DHCP Port Number. The port numbers of protocols such as DHCP, FTP, TELNET, HTTP, SMTP etc. are defined as per RFC 1700.
What is port number ?
The end point of a logical connection is known as port. Port number is logical address of each application or process or program which uses network or internet connection in order to communicate. In TCP/IP network, it helps sender and receiver to communicate with each other. Port number is 16 bit in size which takes any value from 0 to 65536. The port numbers from 0 to 1024 are known as well known ports and are used for specialized services or privileged services. DHCP port numbers used for server and client are 67 and 68 respectively.
IP address and port number are used to deliver data packets to its destination device. IP address resembles to apartment building or flat building housing multiple flats/apartments. The port number resembles to individual apartment or flat number. IP address/port number can be written as 192.168.1.68:8080 where in first four digits are IP address and last digit "8080" is port number.
What is DHCP Protocol?
• DHCP is defined in RFC 2131.
• It runs over UDP.
• It provides automatic configuration of host connected to the network or booted while connected on the network.
• It provides hosts with initial configuration data which includes IP address with subnet mask, default gateway and IP address of the DNS server
• The figure depicts how DHCP works. As shown DHCP client requests for its configuration from DHCP server. Upon receiving the request, DHCP server replies the information to the client. These include IP address, subnet mask, default routers, DNS servers, lease time etc.
• DHCP server dynamically assigns IP address on demand to the DHCP clients.
• DHCP uses UDP port number 67 as destination server and port number 68 for the client.
Refer DNS vs DHCP >> for difference between DHCP and DNS protocols.
Table of port numbers vs Protocols
Port numbers are pre-assigned by IANA (Internet Assigned Numbers Authority). They are specified in RFC 1700. Following table mentions port numbers for FTP, TELNET, HTTP, SMTP, POP3, IMAP, BIOS, SSH, DHCP protocols. These protocols are used in TCP or UDP connections in computer networks.
|Port Number||Protocol description|
|20, 21||port number 20 is used for FTP data while port number 21 is used for FTP Control|
|23||Used for TELNET|
|161||SMTP (Simple Mail Transfer Protocol)|
|143||IMAP i.e. Interim Mail Access Protocol|
|137, 138, 139||port number 137 is used for BIOS Name service, 138 for NetBIOS-dgm, 139 for NetBIOS Datagram service|
|22||Used for SSH remote login protocol, SSH is short form of Secure Shell|
|67, 68||The port number 68 is used for DHCP client and 67 is used for DHCP server|
|53||DNS (Domain Name System)|
|69||TFTP (Trivial File Transfer Protocol)|
|179||BGP (Border Gateway Protocol)|
|389||LDAP (Lightweight Directory Access Protocol)|
Networking related links
Basics of OSI and TCPIP layers
ARP Request and ARP Response
TCP IP packet format
What is Router
What is an IP address
Hub and Types of Hub
What is MAC address