Port numbers-FTP,TELNET,HTTP,SMTP,POP3,IMAP,BIOS,SSH,DHCP
Aug 27, 2019 40 Network Protocols with Port Numbers, Transport Dynamic Host Configuration Protocol (DHCP) 67 and 68: UDP: It is a kind of service used in the client and server model. 9.Post Office Protocol 3 (POP3) 110: TCP: It is a protocol used by e-mail client to retrieve e-mail from the servers. 10.Network News Transport Protocol (NNTP) 119: TCP BOOTP (Bootstrap Protocol) In fact, DHCP is based on BOOTP. The port numbers are the same so you can’t run a BOOTP and DHCP server at the same time. There is a key difference between BOOTP and DHCP though. BOOTP uses a static database that you have to fill yourself. Similar to RARP, you need to enter all MAC addresses and the IP addresses (and other options like a What ports are used by DHCP and the DHCP clients - Answers Requests are on UDP reversed port 68 & Server replies on UDP reversed port 67 If the above is right, then you can allow those ports on Linux(Ubuntu) with: sudo iptables -A OUTPUT -p udp --dport 68
Port numbers-FTP, TELNET, HTTP, SMTP, POP3, IMAP, BIOS, SSH, DHCP. This page describes well known port numbers defined in RFC 1700.It mentions Port numbers for FTP, TELNET, HTTP, SMTP, POP3, IMAP, BIOS, SSH, DHCP used in TCP, UDP and IP protocols. Port Numbers: The end point of a logical connection is known as port. It is a 16 bit size number
Dynamic Host Configuration Protocol - DHCP The following diagram shows the changing port numbers and the source and destination addresses used during the DHCP transaction. UDP port 68 is reserved for DHCP clients, and UDP port 67 is reserved for DHCP servers. Step 1 DHCP Discover Sent by the client looking for the IP address. The source IP is 0 IP Addressing: DHCP Configuration Guide, Cisco IOS Release May 31, 2017 Ports - ThinManager Knowledge Base
In fact, DHCP is based on BOOTP. The port numbers are the same so you can’t run a BOOTP and DHCP server at the same time. There is a key difference between BOOTP and DHCP though. BOOTP uses a static database that you have to fill yourself. Similar to RARP, you need to enter all MAC addresses and the IP addresses (and other options like a
Nov 01, 2013 How To Find The Port Number Of A Service In Linux