CyberCertPrepNetwork FundamentalsCommon Protocols & PortsEASYFree question
Scenario
A network engineer is asked to verify whether a remote server (10.5.5.100) has port 443 open without using a full vulnerability scanner. They want a quick command-line test.
Which command-line tool or technique can quickly test whether TCP port 443 is open on a remote host from a Windows workstation?
- A.telnet 10.5.5.100 443 - the Telnet client attempts a TCP connection to port 443; if it connects (blank screen or TLS handshake data), the port is open; if it fails immediately, the port is closed or filtered
- B.ping 10.5.5.100 -p 443 - ping can test specific ports
- C.nslookup 10.5.5.100 443 - nslookup tests port availability via DNS
- D.tracert 10.5.5.100:443 - tracert supports port specification
Why A is correct