Which traffic does tcp.port==80 match?

• A. Any packet with TCP port 80 as either source or destination
• B. Only packets with source port 80
• C. Only packets with destination port 80
• D. TCP packets on non-80 ports

Answer: (A)

tcp.port==80 matches any TCP packet that has port 80 in either position—the source or the destination. In other words, it’s the combination of tcp.srcport == 80 or tcp.dstport == 80. This is why it correctly selects both directions of web traffic: requests where destination port is 80 (client to server) and responses where source port is 80 (server to client). If you filtered only by source port, you’d miss the client-to-server requests; filtering only by destination port would miss the server’s responses. The filter applies specifically to TCP, not other protocols.