F5 Networks Troubleshooting BIG-IP

Here is a typical case. Users report that a virtual server accepts connections, yet pages never finish loading. You run tcpdump on the client-side VLAN and see the TCP handshake complete. Then you capture on the server-side VLAN and find SYNs leaving BIG-IP with no reply. The problem has moved from “the load balancer is broken” to “the pool member has no return route.” This F5 Troubleshooting BIG-IP training is built around that kind of evidence.

F5’s Troubleshooting BIG-IP course gives packet capture serious lab time. You learn tcpdump options for viewing hex and ASCII payloads, write capture filters so you only collect the connection you need, and save files for analysis. In Wireshark, you build display filters, follow TCP streams, and recognize resets, retransmissions, and stalled transfers.

Encrypted traffic needs a different approach, so the course covers SSL/TLS analysis with tools such as ssldump. Fiddler shows HTTP sessions at the header level, including content types, response codes, and timing. curl lets you test a pool member directly, bypassing the virtual server to see whether the server or BIG-IP is at fault.

Packets are only one source of evidence. The course also teaches a step-by-step troubleshooting method, bottom-to-top checks from Layer 1 through Layer 3, and CPU and memory analysis with tmsh and watch. Log analysis covers BIG-IP log files, logging levels, daemon roles, and iRule-based logging. KDiff3 helps when one device behaves differently from another with a supposedly identical configuration.

Before the troubleshooting starts, you set up a BIG-IP and review local traffic objects and high availability, so the lab environment feels familiar. The F5 support chapter explains iHealth, knowledge articles, and the data to provide when opening a case.

The final lab projects bring the tools together. You diagnose faults the way you would during live data center operations, without the risk of a production outage.

Course Objectives

On completion, you will be able to:

• Capture traffic on BIG-IP with tcpdump, using filters and hex and ASCII output.
• Analyze captures in Wireshark to locate resets, retransmissions, and failed handshakes.
• Examine SSL/TLS sessions with ssldump and HTTP exchanges with Fiddler.
• Isolate server-side faults by testing pool members directly with curl.
• Apply a documented troubleshooting process to each lab fault.
• Diagnose Layer 1 to Layer 3 issues involving interfaces, VLANs, ARP, self IPs, and routing.
• Interpret log files, logging levels, and daemon messages, and add iRule logging when needed.
• Compare configurations with diff and KDiff3 to find unexpected differences.
• Prepare iHealth diagnostics and case information for F5 support.