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Month: August 2017

How to install Nginx in RHEL and CentOS

NGINX is a free, open-source, high-performance HTTP server and reverse proxy, as well as an IMAP/POP3 proxy server. NGINX is known for its high performance, stability, rich feature set, simple configuration, and low resource consumption. To add NGINX yum repository, create a file named /etc/yum.repos.d/nginx.repo and paste one of the configurations below:             CentOS:                         [nginx]                         name=nginx repo                         baseurl=http://nginx.org/packages/centos/$releasever/$basearch/                         gpgcheck=0                         enabled=1             RHEL:                         [nginx]                         name=nginx repo                         baseurl=http://nginx.org/packages/rhel/$releasever/$basearch/                         gpgcheck=0                         enabled=1 Due to differences between how CentOS, RHEL, and Scientific Linux populate the $releasever variable, it is necessary to manually replace $releasever with either 5 (for 5.x) or 6 (for 6.x), depending upon your OS version. Installing nginx through yum is just a command away. and can be done as below: [root@app-node1 ~]# yum install nginx                                                                              Loaded plugins: rhnplugin, security This system is not registered with RHN. RHN support will be disabled. Setting up Install Process Parsing package install arguments Resolving Dependencies –> Running transaction check —> Package nginx.i386 0:0.8.55-2.el5 set to be updated –> Processing Dependency: libGeoIP.so.1 for package: nginx –> Running transaction check —> Package GeoIP.i386 0:1.4.8-1.el5 set to be updated –> Finished Dependency Resolution …. Dependencies Resolved ================================================================================  Package          Arch            Version                 Repository       Size ================================================================================ Installing:  nginx            i386            0.8.55-2.el5            epel            390 k Installing for dependencies:  GeoIP            i386            1.4.8-1.el5             epel            781 k Transaction Summary ================================================================================ Install      2 Package(s) Update       0 Package(s) Remove       0 Package(s) Total download size: 1.1 M Is this ok [y/N]: Y If you encounter dependency issues while installing through yum you can solve that by...

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Simple Steps for Installing Munin Monitoring Tool

Munin the monitoring tool surveys all your computers and remembers what it saw. It presents all the information in graphs through a web interface. Its emphasis is on the plug and play capabilities. After completing an installation a high number of monitoring plugins will be playing with no more effort. Credit goes to munin for developing such a good monitoring tool. Using Munin you can easily monitor the performance of your computers, networks, SANs, applications, weather measurements and whatever comes to mind. It makes it easy to determine “what’s different today” when a performance problem crops up. It makes it easy to see how you’re doing capacity-wise on any resources. Munin uses the excellent RRDTool (written by Tobi Oetiker) and the framework is written in Perl, while plugins may be written in any language. Munin has a master/node architecture in which the master connects to all the nodes at regular intervals and asks them for data. It then stores the data in RRD files, and (if needed) updates the graphs. One of the main goals has been ease of creating new plugins (graphs). This article will help you to install Munin on your system. Step 1: Set Up EPEL Repository First, we need to add an epel repository in our system. Use one of the following commands to install as per system architecture. CentOS/RHEL 6, 32 Bit (i386): #...

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HTTP Status and Error Codes

HTTP, Hypertext Transfer Protocol, is the method by which clients (i.e. you) and servers communicate. When someone clicks a link, types in a URL or submits out a form, their browser sends a request to a server for information. It might be asking for a page, or sending data, but either way, that is called an HTTP Request. When a server receives that request, it sends back an HTTP Response, with information for the client. Usually, this is invisible; though I’m sure you’ve seen one of the very common Response codes – 404, indicating a page was not found. There are a fair few more status codes sent by servers, and the following is a list of the current ones in HTTP 1.1, along with an explanation of their meanings.A more technical breakdown of HTTP 1.1 status codes and their meanings is available at http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html. There are several versions of HTTP, but currently HTTP 1.1 is the most widely used. Informational•    100 – ContinueA status code of 100 indicates that (usually the first) part of a request has been received without any problems, and that the rest of the request should now be sent.•    101 – Switching ProtocolsHTTP 1.1 is just one type of protocol for transferring data on the web, and a status code of 101 indicates that the server is changing to the protocol it defines in...

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Free DNS Tools which helps to Administer your Network

DNS Tools which will help you to administer, troubleshoot, manage, and secure your network. A few you may have heard of it, but most likely at least a few of these free network and DNS tools will be new to you and worth checking out. eToolz: This portable Windows application includes all the common network utilities for diagnosis and troubleshooting, such as NS-Lookup, tracing, whois and ping. It also offers tools for Google PageRank checking, email address verification, retrieving HTTP header info and connecting to Internet time servers. Fing: This network discovery and scanning tool is available for Windows, Mac OS X and Linux computers, as well as Android and iOSmobile devices. The computer versions don’t currently have a GUI and must be used via an interactive command-line interface, but the mobile versions do have a GUI and are great for scanning Wi-Fi networks. Advanced IP Scanner: This network discovery and scanning tool features a Windows GUI. It offers shortcuts to the resources (HTTP, HTTPS, FTP or shared folders) of detected computers and clients. It also supports remote wake up and shut down of remote groups of Windows machines. If you use the Radmin remote access solution, you can also connect to any detect machine with Radmin Server. SpiceWorks: The SpiceWorks solution combines network monitoring, help desk ticketing, UPS power management, RFQ, and PC inventory tools. It also features...

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Use of DNS and Common DNS Record Types

What is DNS ? Domain Name System (or Service or Server), an Internet service that translates domain names into IP addresses. Because domain names are alphabetic, they’re easier to remember. The Internet however, is really based on IP addresses. Every time you use a domain name, therefore, a DNS service must translate the name into the corresponding IP address. For example, the domain name www.example.com might translate to 198.105.222.11. The DNS system is, in fact, its own network. If one DNS server doesn’t know how to translate a particular domain name, it asks another one, and so on, until the correct IP address is returned. The basics of creating A records (which translate a hostname to an IP address) are simple enough TTL (Time to Live) is a setting for each DNS record that specifies how long a resolver is supposed to cache (or remember) the DNS query before the query expires and a new one needs to be done. The benefits of caching are pretty obvious: it’s a lot faster to check your local resolver’s cache then having to look up a DNS record that isn’t already cached. This speed up your Internet experience when visiting a site you go to often (since less time is needed to complete DNS lookups) and also helps lower the load on DNS servers around the world. What happens when the DNS...

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