Linux

Capturing and Replaying Connection-less Protocols (eg. IPFIX into Logstash)

Capture real-world network traffic so you can replay it later / elsewhere for development and testing. An example is given using IPFIX (AppFlow), but directly relevant to UDP Syslog too.

The importance of being liberal in a Cisco environment

Network incompatibilities do happen and sometimes you need to be a little more forgiving in order to let the traffic flow. An example of where some Cisco behaviour was running foul of Linux.