Analyzing SQUID access logs

There are loads of programs on the internet which are squid log analyzers. While this article does address the same thing, it’s presented more with an eye to how you can use standard linux bash scripts to obtain almost any output you want from log files. In the following script I use no python / … Continue reading Analyzing SQUID access logs

Advertisements

Cisco network traffic monitoring with NfSen/NfDump and NetFlow

A while ago I wrote a quick article on using NTOP to monitor network utilization by using cisco’s NetFlow functionality. This is an excellent tool, and it’s high level reporting is definitely a strength. However, I was after a more detailed report about what happened when. In a network, it is often necessary to keep … Continue reading Cisco network traffic monitoring with NfSen/NfDump and NetFlow

PathPing : the forgotten latency tool

One of the biggest network troubleshooting questions has to be “why is my site loading so slow?” (and other related latency questions). A very useful and underutilised tool is built right into the windows OS. This tool is a relative of traceroute and uses ICMP to calculate the latency introduced at different hops along the … Continue reading PathPing : the forgotten latency tool

Tips and Tricks : Fiddler

When troubleshooting website issue (such as parts of the website not loading, infinite redirect loops, and so on) the web debugger tools Fiddler2 comes in handy. This is especially so when troubleshooting HTTPS issues. Wireshark is a bit difficult to use when troubleshooting encrypted sessions because unless you are given the private keys from the … Continue reading Tips and Tricks : Fiddler

Identifying network latency / jitter issues w/ Wireshark

Issue : sporadically and randomly clients would see jitter (picture freezing for a small number of seconds) when viewing live video streams such as BBC news To start tackling the above issue it is first important to observe the normal behaviour of the video stream. In BBC’s case, the video stream is using RTMP (port … Continue reading Identifying network latency / jitter issues w/ Wireshark

Tips / programs for manual log analysis

Any troubleshooting techie will tell you that most of his / her time is spent analysing megabytes of log files trying to figure out what happened, what went wrong and so on. Log files are usually about the only thing left in the aftermath of an incident. In the mad rush to bring systems back … Continue reading Tips / programs for manual log analysis