linux flush dns cache centos 7
Most Relevant Content
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 [...]
- »
How to Add New Domains to BIND DNS Server | July 5, 2019
DNS (Domain Name System) Server is an essential part to any computer network. So, it is always suggest keeping a DNS Server in every network. How to configure a DNS Server with BIND package was discussed in my previous article. A common question among the fresher admins of BIND DNS is how to add a new domain to BIND DNS Server. For this, this article is designed to discuss the proper way to add multiple domains to BIND DNS Server. [...]
- »
MikroTik DHCP Server Configuration in RouterOS 7 | October 14, 2015
Dynamic Host Configuration Protocol (DHCP) is a client/server protocol. DHCP server automatically provides an Internet Protocol (IP) address and other related information such as subnet mask, default gateway and DNS to DHCP clients. DHCP server and client use UDP port 67 and 68 for communication. In a network, a DHCP client (IP devices such as Desktop, Laptop, Smartphone etc.) requests for an IP lease to DHCP servers and a DHCP server responses allocating IP address and other related IP information [...]
- »
Red Hat/CentOS 7 Linux Installation (Minimal Packages) | April 18, 2017
Linux is a free and open source operating system developed by Linus Torvalds on September 17, 1991. It is mainly used as server environment. A lot of Linux distributions are present today. Among them, Red Hat Linux is used as enterprise Linux. Red Hat is also known as Red Hat commercial Linux that means Red Hat is a paid service program. CentOS (Community Enterprise Operating System) is another Linux distribution that provides a free and open source, enterprise-class, community-supported server platform functionally [...]
- »
MikroTik OpenVPN Setup with Windows Client | April 2, 2018
VPN (Virtual Private Network) technology provides a secure and encrypted tunnel across a public network. So, a private network user can send and receive data to any remote private network through VPN tunnel as if his/her network device was directly connected to that private network. MikroTik OpenVPN Server provides a secure and encrypted tunnel across public network for transporting IP traffic using PPP. OpenVPN uses SSL Certificates. So, OpenVPN Tunnel is a trusted tunnel to send and receive data across [...]
- »
GNS3 Installation and Configuration Step by Step in Windows | September 14, 2018
GNS3 (Graphical Network Simulator) is one of the most popular network simulator software used by hundreds of thousands of network engineers worldwide to emulate, configure, test and troubleshoot virtual and real networks. GNS3 supports a large number of vendors such as MikroTik, Cisco, Juniper, Windows, Linux and many other vendors. GNS3 can be installed on Windows, Linux and MAC Operating System. In this article, I will show how to download and install GNS3 application in Windows Operating System. I will [...]
- »
MikroTik SSTP VPN Server Configuration with Windows 10 | April 27, 2020
VPN (Virtual Private Network) technology provides a secure and encrypted tunnel across a public network. So, a private network user can send and receive data to any remote private network through VPN tunnel as if his/her network device was directly connected to that private network. Secure Socket Tunneling Protocol (SSTP) transports PPP tunnel over TLS channel. SSTP uses TLS channel over TCP port 443. So, SSTP VPN can virtually pass through all firewalls and proxy servers. Because of using TLS [...]
- »
MikroTik Backup and Restore Configuration using Winbox | July 31, 2018
Backup and Restore feature in MikroTik Router helps to recover router configuration when running router fails to operation due to hardware failure. If you have a backup copy of your failed router and purchase a new MikroTik Router and then upload and restore that backup file, you will get your running network without any hassle. MikroTik Backup file is also useful when you unfortunately forget your admin privilege user password. You can easily recover your forgotten password with backup file [...]
- »
Securing MikroTik Router with Port Knocking | March 21, 2021
MikroTik Port Knocking strategy helps to protect MikroTik Router from hackers and unauthorized access as well as enhances MikroTik RouterOS security.
- »
MikroTik Hotspot Login Page with Random MAC Detection | October 5, 2025
Hotspot businesses such as cafés, restaurants, co-working spaces, schools, and ISPs often rely on MikroTik Hotspot solutions to provide Wi-Fi access. One common challenge is that many modern devices (Android, iOS, Windows, macOS) use randomized (private) MAC addresses, which can cause repeated logins, loss of session persistence, and difficulties with usage tracking. To solve this problem, we have designed a professional Hotspot Login Page Template that not only looks modern and mobile-friendly but also detects randomized MAC addresses and notifies [...]
You May Also Like
