How to Filter Network Traffic by TCP/UDP Ports in Wireshark

tcp.port == <port number>

For example, to filter for TCP traffic on port 80 (HTTP):

tcp.port == 80

To filter for UDP traffic on a specific port, use:

udp.port == <port number>

For example, for UDP traffic on port 53 (DNS):

udp.port == 53

You can also combine these to filter for both TCP and UDP traffic on the same port:

tcp.port == 80 || udp.port == 80

Display filter syntax is detailed here and some examples can be found here and a port filter for tcp is tcp.port == <port number> and for udp is udp.port == <port number>.

Let me know if you have any other questions!