netwyman

What is the Internet Control Message Protocol (ICMP)? The Internet Control Message Protocol (ICMP) is a network layer protocol used by network devices to diagnose network communication issues. ICMP is mainly used to determine whether or not data is reaching its intended destination in a timely manner. Commonly, the ICMP protocol is used on network devices, such as routers. ICMP is crucial for error reporting and testing, but it can also be used in distributed denial-of-service (DDoS) attacks. What is ICMP used for? The primary purpose of ICMP is for error reporting. When two devices connect over the Internet, the ICMP generates errors to share with the sending device in the event that any of the data did not get to its intended destination. For example, if a packet of data is too large for a router, the router will drop the packet and send an ICMP message back to the original source for the data. A secondary use of ICMP protocol is to perform network diagnostics; the...

Linux Firewall Tools The Linux kernel is part of every Linux distribution. This also includes a Linux firewall called   netfilter . You can control the Linux Firewall with the Command Line Utility   iptables . Debian-based distributions like Ubuntu or Knoppix have no predefined rules during the installation, so everything is allowed by default. With Enterprise Linux distributions such as Fedora, CentOS or RedHat, use ports have to be opened manually. The configuration of the Linux firewall can be adapted to your needs using   iptables . However, the syntax and handling of   iptables   is relatively complex, so there are several tools / scripts to configure   iptables . We will introduce you to a small selection here. Tools for the command line to configure your Linux firewall Arno’s Firewall   – Secure firewall for single and multi-homed systems. Very easy to configure, handy to manage and highly customizable. Ferm   –...