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 [...]
- »
MikroTik Site to Site EoIP Tunnel with IPsec | March 21, 2018
VPN (Virtual Private Network) is a technology that provides a secure tunnel across a public network. A private network user can send and receive data to any remote private network using VPN Tunnel as if his/her network device was directly connected to that private network. MikroTik provides EoIP (Ethernet over IP) tunnel that is used to create a site to site VPN. EoIP tunneling is a MikroTik RouterOS protocol that creates an Ethernet tunnel between two MikroTik Routers on top [...]
- »
How to Assign Static IP Address in Windows OS | September 16, 2015
Communication between one computer to another computer or server is established with IP addresses. Without IP address no communication is possible in computer network. An Internet Protocol (IP) Address is a numerical value or label assigned to each electronic device (e.g., computer, smartphone and printer) which uses Internet Protocol for communication. IP can be assigned both dynamically and statically on a IP devices. Dynamic IP is assigned by a DHCP server. If a DHCP server is present in a network, [...]
- »
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 [...]
- »
Essential Networking Skills for Job Seekers in IT industry | March 18, 2025
The Information Technology (IT) industry is one of the most dynamic and rapidly evolving fields in the modern job market. With continuous advancements in technology, businesses are always on the lookout for skilled IT professionals who can adapt to new trends, troubleshoot complex systems, and enhance cybersecurity measures. However, technical knowledge alone is not enough to secure a job in the IT industry. One of the most critical factors in landing a job and advancing in an IT career is [...]
- »
MikroTik Hotspot Auto Login by MAC Address | July 1, 2020
Hotspot is an awesome service in MikroTik Router. MikroTik Hotspot is popularly used in ISP, Hotel, Airport, Coffee Shop, Enterprise office and many other organizations. By default MikroTik Hotspot uses HTTP CHAP login method where user must provide username and password to get internet service. Sometimes we may face that some users are not eager to provide username and password to get internet service or we cannot ask some users to put username and password to get internet due to [...]
- »
MikroTik Wireless AP Configuration with DHCP using Winbox | October 22, 2019
MikroTik Wireless Router is one of the most popular and stable WiFi Routers. WiFi Zone for an ISP or for an office or for a home can easily be configured with MikroTik WiFi Router. MikroTik has a lot of WiFi Routers that can be used as a WiFi Access Point (AP), a WiFi Station or a WiFi Repeater. MikroTik Wireless Router can also be used as both WiFi Station and WiFi AP simultaneously. The simple usage of MikroTik Wireless Router [...]
- »
MikroTik CAPsMAN and CAP Basic Configuration using Winbox | February 20, 2020
MikroTik CAPsMAN (Controlled Access Point system Manager) is a centralized Access Point management application provided by MikroTik. MikroTik introduces CAPsMAN from RouterOS v6.11 with CAPsMAN v1 and from RouterOS v6.22rc7 CAPsMAN v2 is running. If you have multiple MikroTik CAPs (Controlled Access Point) in your organization, CAPsMAN provides an easy way to maintain client data as well as CAPs configuration centrally. In my previous article, I discussed how to configure MikroTik Wireless Router as an Access Point. In this article, [...]
- »
MikroTik Radius Configuration with FreeRADIUS and MySQL | December 18, 2018
FreeRADIUS is a modular RADIUS suite. A lot of modules such as Perl, python, MySQL etc. can be integrated with freeRADIUS to enrich freeRADIUS features. MySQL is one of the best user and client sources in freeRADIUS server. One of the important advantages of MySQL with freeRADIUS server is that MySQL can easily be controlled with a lot of programming languages including PHP. So, freeRADIUS users and their authentication, authorization and accounting can easily be controlled graphically using MySQL database [...]
- »
Firewalld Installation and Configuration in Ubuntu Server | May 5, 2022
Firewalld is an awesome host based firewall management tool for Linux Operating System. Firewalld has developed on Fedora but it is now available for almost all Linux distributions. So, Firewalld can be installed in Ubuntu Server although Ubuntu Server has UFW as the default firewall system. Firewalld is more robust and easy to maintain than UFW, I think. So, I am going to discuss how to install and configure Firewalld in Ubuntu Server. Installing Firewalld in Ubuntu Server By default [...]
You May Also Like
