Let’s Encrypt is a non-profit certificate authority that provides X.509 certificates for Transport Layer Security (TLS) encryption free of cost. The TLS certificate is valid for 90 days only. However, Due to the bug, they need to revoke many (read as “certain”) Let’s Encrypt TLS/SSL certificates. Let us see how to find out if you are affected by this bug and how you can fix it to avoid any problems with your TLS/SSL certificates.
OpenBSD version 6.3 has been released. OpenBSD is demonstrating to be an excellent server operating system. Security is more critical now than ever before. OpenBSD leads the pack when it comes to security features. OpenBSD provides a very robust and trustworthy system that comes with the cutting-edge security feature. OpenBSD 6.3 continues to offer the “multi-platform, ultra-secure operating system” experience. The OpenBSD team releases a new version every six months.
Continue reading “OpenBSD 6.3 released ( Download of the day )”
I recently installed TomatoUSB advanced firmware on my Asus RT-AC66U wifi router. This router act as my wireless Ethernet bridge. TomatoUSB advanced has additional features like
- Multiple WAN support (3G/4G/Static IP/Cable/ADSL2)
- Virtual Wireless
- FTP/Media server via USB
- BiTorrent Client via USB
- UPS support
- OpenVPN client and server
- Tinc VPN server and much more.
If you want to monitor network throughput on the command line interface, use nload application. It is a console application which monitors network traffic and bandwidth usage in real time. It visualizes the in and outgoing traffic using two graphs and provides additional info like total amount of transferred data and min/max network usage.
The nicstat command is top like utility for network interface card (NIC). It displays information and statistics about all your network card such as packets, kilobytes per second, average packet sizes and more. It works under Solaris and Linux operating systems.
In this post, I will explain how to install and use the nicstat command to find out stats about your NICs under Debian / Ubuntu / RHEL / CentOS Linux operating systems.
Nmap is short for Network Mapper. It is an open source security tool for network exploration, security scanning and auditing. However, nmap command comes with lots of options that can make the utility more robust and difficult to follow for new users.
The purpose of this post is to introduce a user to the nmap command line tool to scan a host and/or network, so to find out the possible vulnerable points in the hosts. You will also learn how to use Nmap for offensive and defensive purposes.
The HTTP 2xx class of status codes indicates the action requested by the client was received, and processed successfully. HTTP/1.1 200 OK is the standard response for successful HTTP requests. When you type www.cyberciti.biz in the browser you will get this status code. The HTTP/1.1 206 status code allows the client to grab only part of the resource by sending a range header. This is useful for:
- Understanding http headers and protocol.
- Troubleshooting network problems.
- Troubleshooting large download problems.
- Troubleshooting CDN and origin HTTP server problems.
- Test resuming interrupted downloads using tools like lftp or wget or telnet.
- Test and split a large file size into multiple simultaneous streams i.e. download a large file in parts.
You can setup a wireless connection between two routers only so that it will link a wireless network to a wired network allowing you to bridge two networks with different infrastructure. You can find wireless access points products that offer either a “bridge” mode or a “repeater” mode. In this post I’m going to explain three popular open source choices that can be used for setting up a wireless bridge.
Most embedded Linux / BSD systems such as routers, servers and nas devices comes with console interface (serial port with RS-232). BIOS can uses this, and after boot BIOS screen I/O is redirected so that you can use the device. RS-232 is also used for communicating to headless server, where no monitor or keyboard is installed, during boot when operating system is not running yet and therefore no network connection is possible. You need to use a serial cable between your computer and embedded system or server. In this post I will cover five conman utilities used for serial communication under Linux / Unix / *BSD and Mac OS X.