Explain Application Client-Server Communication F5CAB5 Practice Questions (Page 4)

Questions 16–20

1. 16application · medium

   A network administrator is troubleshooting an issue where a client cannot connect to a web server. A packet capture shows the client sending a SYN packet, then receiving a SYN-ACK, and then sending an ACK. However, the application-level request never reaches the server. Which layer of the communication process is most likely the problem?

   • AThe TCP connection is established, but the HTTP request is not being transmitted or is being blocked.
   • BThe client is using the wrong destination port, so the server rejects the connection.
   • CThe server is not listening on the port, so the handshake fails.
   • DThe TCP three-way handshake is incomplete because the final ACK was not sent.
   Reveal Solution Discussion Select an answer first
2. 17application · medium

   A user reports that typing 'https://www.example.com' in a browser fails with a 'Server not found' error, but the server is reachable when the user enters 'https://192.0.2.10' directly. The BIG-IP system is not involved in DNS resolution. Which step in the client-server communication process is most likely failing?

   • AThe server is not listening on the default HTTPS port 443.
   • BThe client cannot establish a TCP connection to the server's IP address.
   • CThe client's HTTP request is being blocked by a firewall.
   • DThe client cannot resolve the domain name to an IP address via DNS.
   Reveal Solution Discussion Select an answer first
4. 18foundation · easy

   Which default port is used by HTTPS for secure web traffic?

   • A443
   • B25
   • C21
   • D80
   Reveal Solution Discussion Select an answer first
5. 19foundation · easy

   What is the correct sequence of packets in the TCP three-way handshake?

   • AACK, SYN, SYN-ACK
   • BFIN, ACK, FIN-ACK
   • CSYN, SYN-ACK, ACK
   • DSYN, ACK, SYN-ACK
   Reveal Solution Discussion Select an answer first
6. 20expert · hard

   A BIG-IP administrator is configuring a virtual server for an application that requires the client's IP address to be logged by the server. The server is in the same subnet as the BIG-IP, and the BIG-IP is not the default gateway for the server. The administrator wants to avoid SNAT to preserve the client IP. However, the server logs show the BIG-IP's self IP. What is the most likely reason?

   • AThe virtual server is configured with SNAT Automap.
   • BThe BIG-IP is performing NAT on the destination IP, not the source.
   • CThe server is not configured to accept traffic from the client's subnet.
   • DThe client's IP is being hidden by the BIG-IP's HTTP profile.
   Reveal Solution Discussion Select an answer first