Linux Terminal Command Reference. Fail2Ban (with iptables) And Asterisk. Fail2Ban is a limited intrusion detection/prevention system. It works by scanning log files and then taking action based on the entries in those logs.We are implementing Fail2Ban with a configuration to be able to prevent SIP brute force attacks against our Asterisk PBXs.You can get Fail2Ban, as well as more documentation, at www.fail2ban.org. At the time this is being written, the current release is 0.8.4.The following describes how to setup Fail2Ban to protect an Asterisk PBX from SIP brute force attempts and scans utilizing the iptables firewall. SECURITY NOTE: fail2ban is rather limited in its ability to detect attacks against asterisk. More info a more comprehensive product like SecAst www.generationd.com Easy Install Script for Fail2ban version 0.8.4 / Red Hat Before running it, you will have to do chmod 755. Download script with new dedicated sources : Installing yum install fail2ban Debian/Ubuntu: apt-get install fail2ban.
Fail2ban. CoreOS. Tools | NIL - Network Information Library. 20 Linux System Monitoring Tools Every SysAdmin Should Know. Need to monitor Linux server performance? Try these built-in commands and a few add-on tools. Most Linux distributions are equipped with tons of monitoring. These tools provide metrics which can be used to get information about system activities. You can use these tools to find the possible causes of a performance problem.
The commands discussed below are some of the most basic commands when it comes to system analysis and debugging server issues such as: Finding out bottlenecks.Disk (storage) bottlenecks.CPU and memory bottlenecks.Network bottlenecks. #1: top - Process Activity Command The top program provides a dynamic real-time view of a running system i.e. actual process activity. Fig.01: Linux top command Commonly Used Hot Keys The top command provides several useful hot keys: => Related: How do I Find Out Linux CPU Utilization?
#2: vmstat - System Activity, Hardware and System Information Display Memory Utilization Slabinfo # vmstat -m Get Information About Active / Inactive Memory Pages. How To Set Caching DNS Server. Q. How do I set caching dns server to speed up dns lookup for my LAN (500 PC)? The DNS lookups creating a lot of network activity. There are a few times when this causes performance issues. How do I configure caching dns under Debian Linux? A. Often many users and running daemon can perform tons of dns lookup. This can create problems for slow network connections as well the latency of the lookup can slow down overall experince for end users. Dnsmasq is a lightweight DNS, TFTP and DHCP server. Step # 1: Install dnsmasq Simply, type the following command under Debian / Ubuntu Linux: # apt-get install dnsmasq Red Hat, Fedora / CentOS Linux user can grab dnsmasq rpm here or just enter: # rpm -ivh Step # 2: Configure dnsmasq Open /etc/resolv.conf # vi /etc/resolv.conf Set up upstream DNS servername i.e add ISP name server: nameserver 202.1.10.10 nameserver 203.2.10.10 nameserver 203.3.10.10 Save and close the file.