A single port can be configured to listen for UDP or TCP inbound connection requests (or both). Telnet uses TCP. So when you telnet to a specific IP:port, telnet will attempt to make a TCP connection. If there is no TCP listener on the port you specify, then the connection request will be refused. It matters not if you have a UDP listener on the port. Telnet will not be able to establish a connection to a UDP port.
No, it uses TCP. See related link
Port 69 and UDP are used for tftp transmissions.
UDP: DNS, TFTP, DHCP... TCP: SMTP, HTTP, HTTPS, DNS, FTP, SHH, Telnet...
Port No. for Tranmission Control Protocal (TCP) is 6 Port No. for User Datagram Protocol (UDP) is 17
UDP port 123. (UDP is a connectionless protocol that sacrifices reliability for speed and bandwidth).
There are a lot of differences between a DNS port and UDP. An example would be DNS is for translation while UDP actually relays the host communication.
DHCP is a layer-4 protocol, most commonly transported over UDP. UDP port number 67 is the destination port of a server, and UDP port number 68 is used by the client
Port 1151 is used for TCP/UDP
ICMP does not have a port like TCP and UDP.
RIP uses UDP protocol with port number 520
Port 69 and UDP are used for tftp transmissions.
both tcp and udp