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DNS Server Configuration on CentOS 7 (Caching DNS with BIND)
DNS (Domain Name System) Server is an essential part to any computer network. Today web communication cannot imagine without DNS Server. DNS is a client server protocol where DNS Client requests for the domain name resolution and DNS Server response on it. Every network should have a DNS Server because local DNS Server improves network performance by caching DNS information and serving DNS request locally. DNS Server can be configured either Windows or Linux operating system. In this article, I will discuss how to configure a caching DNS Server on CentOS 7/ RedHat 7 Linux with BIND9 Service. Domain Name System (DNS) and How It Works Communication between a workstation (PC) and a Server are always done by IP address. So, to get any information from any Web Server, you have to remember the IP address of that Server. But remembering a huge number of public IP addresses is almost impossible for the human being. To solve this issue, DNS technique is introduced in computer networking. The DNS technique can be best compared to a phone book where a user finds a phone number listed by the easier-to-remember name. So, the DNS can be defined as a mapper between human [...]
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Internet Content Filtering in MikroTik Router using OpenDNS | August 22, 2024
Internet content is always not safe for our work or home network. We always face malware, phishing and adult content which are harmful for office or home internet. Using web content filtering software, we can easily get rid of this harmful content. OpenDNS is a cloud-based internet content filtering solution that helps to keep our office or home internet free from malware, virus and adult content. Configuring Free OpenDNS Home Internet feature with our Home WiFi Router, we can easily [...]
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How to Prevent Simultaneous User Login in MikroTik Hotspot | November 10, 2020
MikroTik Hotspot is a user based internet access system. Most of the user authentication and authorization can be controlled with MikroTik Hotspot. But sometimes some users misuse user based authentication system. Misusing simultaneous login is one of them. Usually we provide one username and password for a user and we expect he/she will use this username and password from only one device at a time. But it is also possible to use same username and password in multiple devices at [...]
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CentOS 7.5 Installation with GUI and LVM Partition | March 7, 2019
Red Hat/CentOS Linux is a popular server operating system. Specially who work on mail server, web server, web proxy server, ftp server and file server are so familiar with the Red Hat/CentOS Linux. In my previous article, I discussed how to install CentOS 7.5 Linux step by step with the standard partition. But if you want to work on mail server, web proxy server, ftp server, file server or any other application where disk space changes frequently, the standard partitioning [...]
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Enable F8 Menu to Enter Safe Mode in Windows 8 & 10 | August 27, 2015
Windows is the most popular operating system in the world. No computer user can go a single day without windows operating system. As windows is a popular operating system, it has a lot of viruses also. But windows provides various tools for removing these viruses. For removing any unwanted program, windows safe mode is a best option. A popular way to open windows safe mode is windows Advanced Boot Options. Advanced Boot Options provides different run levels for windows users so [...]
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MikroTik DHCP Server Configuration with Radius Server | January 24, 2018
The Dynamic Host Configuration Protocol (DHCP) is a client-server protocol that is used to assign an IP address and other network configuration parameters dynamically to each device on a network so that they can communicate with other IP networks. DHCP Server is popularly used in an Enterprise Office Network because in an office network various types of IP devices such as Laptop, Desktop, Tablet, Smartphone, IP Phone and so on are maintained and almost all IP devices support DHCP. An ISP Network can also be [...]
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Restrict Internet Access Based on MAC Address in MikroTik | February 4, 2017
MikroTik router has a lot of features by which a network administrator can design his network as he likes. As a network administrator, sometimes you may need to allow internet access some specific devices. If other devices try to access internet, they will be rejected by your router. For example, say, you have configured a simple network like below diagram. In this network, you have configured WAN, LAN, Gateway, DNS and NAT. Also you have created queue rules for limiting [...]
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MikroTik User Manager RADIUS Installation on RouterOS 7 | July 5, 2022
The User Manager is a MikroTik provided RADIUS Server packages. It can be used to manage users for small or medium level business. User Manger is not a default RouterOS packages. So, we have to install user manager as an extra package in RouterOS 7. RouterOS 7 has brought a massive change on User Manager package. The most important change is managing User Manager from Winbox while in RouterOS 6 the User Manager package can only be managed from Web [...]
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Hardening MikroTik RouterOS by Limiting Login Services | February 6, 2021
MikroTik RouterOS is usually used as a bridge between WAN and LAN network. WAN network is always an insecure network because attackers always try to hack your RouterOS so that they can compromise it for their own benefit. As a network administrator of MikroTik RouterOS, we should always take anti hacking steps to secure our MikroTik RouterOS. There are a lot of security tasks those we should take care to secure our MikroTik RouterOS. Among these security tasks, we will [...]
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CAPsMAN Channel Planning with Non-Overlapping Frequency | March 16, 2020
MikroTik CAPsMAN is an excellent application for managing multiple CAPs (Controlled Access Point) in a Wireless Network. But multiple APs create frequency overlapping issue if channels are not configured properly. Channel overlapping is required for smooth connection while roaming but there should not be frequency overlapping because frequency overlapping makes wireless performance so poor. In my previous article, I discussed MikroTik CAPsMAN basic configuration with default channel configuration. In this article, I will discuss how to configure CAPsMAN channel to [...]
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