I’ve worked with a various load balancing systems (LBS). They are complex pieces of hardware and software. In this post I will highlight some of the open source load balancing software. But what is load balancing? It is nothing but a technique used to share (spared) load / services between two or more servers. For […]
Explains how to use netstat command to display current connections and find out if your server is under DoS attack or not.
You can use traditional netstat / lsof command to lists open Internet or UNIX domain sockets on FreeBSD. FreeBSD comes with a simple and easy to use command called sockstat. The -4 option only displays IPv4 sockets. The -6 option only displays IPv6 sockets. The -c option only displays connected sockets. The -l option only […]
A TOP-like tool for monitoring system latency and its causes for Linux system. The Intel Open Source Technology Center is pleased to announce the release of version 0.1 of LatencyTOP, a tool for developers to visualize system latencies. Skipping audio, slower servers, everyone knows the symptoms of latency. But to know what’s going on in […]
You can test your IDS or IPS devices to monitor your scan traffic. Use this feature to avoid detection with nmap. You may not want to get caught performing a network scan. For example, using following technique you can test your own IDS / IPS / network security from remote location or home. nmap Decoy […]
Most Linux admins are not aware of hidden switch (undocumented switch) called -D. The -D option display a nice summery of disk I/O subsystem since boot time. Output includes total time spent reading and writing data, merged reads and merged writes (kernel disk i/o optimization technique) and other parameters.
Under Linux operating system you can use the faillog command to display faillog records or to set login failure limits. faillog command displays the contents of the failure log from /var/log/faillog database file. It also can be used for maintains failure counters and limits. If you run faillog command without arguments, it will display only list of user faillog records who have ever had a login failure.