Bifalgorithm post

"Quick network interview question. What port does ping use? If your brain immediately starts thinking about TCP or UDP port numbers, that is a trap. Ping does not use a TCP port. Ping does not use a UDP port. Ping uses ICMP and ICMP is a different protocol. all together. When people are talking about common application ports, they usually mean TCP or UDP ports. They help a device say, this traffic is for this application or service. Web traffic might use TCP 443 for HTTPS, DNS might use UDP 53 or TCP 53 depending on what's happening. But Ping is not trying to connect to an application listening on a port. It is usually sending an waiting for an ICMP echo reply. That is why this is a good interview question. Not because knowing ping makes you a genius, it doesn't, but because it shows whether someone is memorizing random port numbers or actually understands not all network traffic works the same way. That changes how you troubleshoot. If ping fails, that does not automatically mean the server is down. ICMP might just be ignoring it. A firewall might allow the application traffic but deny the ping. So the better answer is ping does not use support, it uses ICMP, and ICMP can be allowed or blocked separately from TCP and UDP services. That answer tells me you understand the shape of the problem. Don't worry, you're not alone. I want everyone who got it right to put a question down in the comments and keep this train rolling. Ask a network question and see who can respond."

"Quick network interview question. What port does ping use? If your brain immediately starts thinking about TCP or UDP port numbers, that is a trap. Ping does…