Linux, Windows, Security, Programming, Network Tutorials
Operating systems like Windows, Linux, BSD runs some mechanisms to cache DNS records in the local system. Caching DNS records locally gives less bandwidth and fast internet access to the user. In this post, we will look at how to flush DNS cache in the operating systems like Windows and Linux (Ubuntu, CentOS, Fedora, Debian, … Read more
Domain Name System is a system or concept used to name hosts connected to the network. DNS is hierarchical which means there is a tree-like connection in the domain names. DNS is invented by Paul Mockapetris in 1983. What is Domain Name A domain name identifies hosts connected to the network. Domain names are unique. … Read more
Hi, collecting logs are important. In my daily job, I am working with logs about a lot of systems like WMware, Application, Linux, Windows, Cisco, checkpoint, pfSense. Logs provide info about the system, application, etc. Security incident management systems heavily rely on logs. Example Log Logs consist of date system name and event detail like … Read more
Hi, today we will look to configure Cisco routers and switches with a password. It may be seen as trivial but very important for security because a lot of issues a password related. Network devices use a lot of protocols to work and these protocols needs security. Authentication resides in security and the first rule … Read more
Today we will look for setting Cisco devices hostname and then disable domain lookup. The hostname is used to identify devices in a meaningful and easy way. Change Hostname First, we change the hostname to ismailbaydan.com and then fall back to default hostname which is Switch S1#configure terminal S1(config)#hostname ismailbaydan.com ismailbaydan.com(config)# ismailbaydan.com(config)#default hostname Switch(config)# Enable … Read more
Proxy is an intermediate system that manages communication between two systems. In web applications, an HTTP proxy is mostly used type. The client makes a request to the proxy and then proxy makes the request to the server behalf of the client. So we may think that why we need an intermediary system for this … Read more
Hi, today we will look for some networking stuff. Up to now, I have not written any routing-related technical post. In this article, I am gonna show you some simple dynamic routing with RIP protocol. Routing is divided into two part which one is static. In static routing, routes are configured in the router by … Read more
Hi. Today we will look for changing the system time and prompt. You may think that what is the relation between system time and prompt, you are right there are no relation:). System time is important for network devices because logs get meaning with them and ACL, VPN time limitations work truly with them. In … Read more
Today we will look SNMP in Linux operating systems. Simple network management protocol named SNMP is designed for getting info and setting configuration in its entities. These entities may be a switch, router, pc, cabinet, printer, etc. Snmp was very popular in the 2000s. Today it is popular too but used for information gathering. What … Read more
Ssh is a protocol designed to make network connections between hosts secure. Ssh is a defacto standard for Linux and related operating systems. Ssh encrypts the connection between sides. Ssh gives terminal access between host and server. To get a terminal there need to be an authentication process. The authentication process is generally password-based but … Read more