In this article, we will show you how to set up multiple SSL Certificates on a CentOS with Apache using a single IP address only. In general, a website administrator is restricted to use a single SSL Certificate per socket with an IP which will cost a lot of investment to the company. This restriction may lead them to buy multiple IP addresses for HTTP’s websites for their domain hosting or buy hardware that allows them to utilize multiple network adapters.This is allowed by an extension to the SSL protocol called Server Name Indication (SNI). Most current desktops and mobile ... Read More

In this article we will learn and configure NFS (Network File System) which is basically used to share the files and folders between Linux systems. This was developed by Sun Microsystems in 1980 which allows us to mount the file system in the network and remote users can interact and the share just like local file and folders.Features of NFSNFS can be configured as a centralized storage solution.No need of running the same OS on both machines.Can be secured with Firewalls.It can be shared along with all the flavors of *nix.The NFS share folder can be mounted as a local ... Read More

Netstat is a command line utility that can be utilized to list out all the network (socket) connections on a method comparable to network connections, routing tables, interface records, masquerade connections, multicast memberships etc. This article explains about – Top 10 Netstat Command Examples on Linux.Listening and non-listening socketsTo show about listening and non-listening sockets, use the following command –$ netstat -allThe sample output should be like this –Active Internet connections (servers and established) Proto Recv-Q Send-Q Local Address Foreign Address State tcp 0 0 localhost:mysql *:* LISTEN tcp 0 0 linux-Inspiron-3:domain *:* LISTEN tcp 0 0 linux-Inspiron-35:46930 ec2-54-236-207-15:https ESTABLISHED ... Read More

This article will help you to create IPtables rules that you can directly use for your daily or routine needs, These examples will act as basic templates for you to work on iptables with these rules which suit your specific requirement.Deleting the IPtables or Existing RulesBefore you start building new IPtables set of rules, you should clean up all the default rules, and existing rules. Use the IPtables flush command, below are some examples –#iptables --flush (or) # iptables --FDefault Policies ChainThe default policy is ACCEPT, change the policy to DROP for all the INPUT, FORWARD, OUTPUT.# iptables -P INPUT ... Read More

Both VPN and Proxy are used to connect to a remote system where one can access the host system from a remote location. However, VPNs are superior than Proxy servers because a VPN can protect your privacy and security by routing your traffic via a secure VPN server and encrypting it. A Proxy, on the other hand, just routes your traffic via a mediating server and it does not provide any additional security.Read through this article to find out more about VPN and Proxy and how they are different from each other.What is a Virtual Private Network (VPN)?A virtual private ... Read More

There are various application programs that we can use to access the resources of a remote machine. Telnet and SSH are the primary client server application programs that use remote terminal service which allows a user at one site to interact with a remote timesharing system at another site as if the user’s keyboard and a display is connected directly to the remote machine. Telnet and SSH both are Layer7 application layer protocols and both use TCP (Transmission Control Protocol) at the transport layer. In this article, we will discuss the important differences between SSH and Telnet. But before going ... Read More

Multitasking plays an important role in the context of defining the performance of a computer. Multitasking decides how processes are divided and performed by the CPU between different inputoutput subsystems. In order to process multiple tasks most efficiently, computer systems use various methods to schedule the tasks, speed up calculations and improve Web browsing among which Spooling and buffering are the primary methods. In this article, we will discuss the major differences between spooling and buffering. But before going into the differences, let's have a basic overview of spooling and buffering so that it will become easier to understand how ... Read More

QoS traffic scheduling is a scheduling methodology of network traffic based upon QoS (Quality of Service). Here, the frames or packets are mapped to internal forwarding queues based on its QoS information, which are then services according to a queuing scheme.Typically, multiple queues are present each with different priority levels. The scheduler decides the type of treatment to be given to the traffic in each queue. When traffic is available, the scheduler maps it to the appropriate queue. For example, video and voice traffic are kept is queued with higher priority than background traffic.Notable QoS Traffic Scheduling MethodsWeighted Round Robin ... Read More

Worldwide Interoperability for Microwave Access (WiMAX), is a wireless microwave technology based on the IEEE 802.16 standards. It was originally published in 2001 by WiMAX forum, the version which is now called fixed WiMAX. It is similar to Wi-Fi, though it provides higher data rates up to 1 Gbps even at distances of 30 miles.WiMAX forum defines WiMAX as – A standards-based technology enabling the delivery of last-mile wireless broadband access as an alternative to cable and DSL.Features of WiMAXWiMAX is a coalition of wireless industry based upon IEEE 802.16 standards.It aims for the advancement of broadband wireless access (BWA) ... Read More

IEEE 802.16 is a standard that defines Wireless Interoperability for Microwave Access (WiMAX), a wireless technology that delivers network services to the last mile of broadband access.The IEEE 802.11 standard that lays down the specifications of the wireless local area networks (WLAN) or Wi-Fi, that connects wireless devices within a limited area.The following chart gives a comparison between 802.16 and 802.11 −FeatureIEEE 802.16IEEE 802.11TechnologyDefines WIMAX.Defines WLANs or WiFi.Application AreaLast-mile of broadband wireless access.Limited area forming wireless LANs.Versions of the Standard802.16a, 802.16d, 802.16e, 802.16m etc.802.11a, 11b, 11g, 11n, 11ac, 11ad etc.Domain of UsageIt is used for a wide area mostly outdoors.It ... Read More