Does SSH use TCP or UDP? Is SSH over TCP or UDP? SSH usually runs over TCP. That being said, RFC 4251 specifies that SSH transmission layer protocol “might also be used on top of any other reliable data stream”. SSH protocol’s default settings are to listen on TCP port 22 for connections.
Which port is DNS? The answer is DNS is mostly UDP Port 53, but as time progresses, DNS will rely on TCP Port 53 more heavily.
Is DHCP a TCP or UDP? The DHCP employs a connectionless service model, using the User Datagram Protocol (UDP). It is implemented with two UDP port numbers for its operations which are the same as for the bootstrap protocol (BOOTP).
Is DNS TCP or UDP? DNS uses TCP for Zone transfer and UDP for name, and queries either regular (primary) or reverse. UDP can be used to exchange small information whereas TCP must be used to exchange information larger than 512 bytes.