Network Testing & Debugging – PCAP Analysis (Part 1)

Whenever you are setting up a network, changing a network, or optimizing a network, things always end up going wrong. When things aren’t working as expected, the best thing you can do is to take a packet capture (pcap) and look at what’s actually going on....

9 Sets of Sample tc Commands to Simulate Common Network Scenarios

Let’s say you want to set up a test network. You have your client, your server, your device under test (in our case, our WarpTCP proxy), and one or two tc boxes. The tc boxes are just little linux boxes with bridged interfaces set up to forward traffic. Plus we...

Performance Testing with cURL, Part 2: Scripting

This is part 2 of a series. Click here to read part 1. Parallel cURL Testing To perform multiple curl transfers in parallel, we need to look at another tool: xargs. If you aren’t familiar with xargs, it is a very powerful linux utility.  With it, we can execute...

Performance Testing with cURL, Part 1: Basics

Overview The cURL program is widely available across many different platforms, which makes it an obvious choice for network testing. It is simple, scriptable, and flexible – which is why it is so powerful. It supports many protocols, but we are going to focus on HTTP...