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Articles That Might Interest:
TCP Header Anaylsis - Section 5: TCP Window Size…
Our fifth section contains some very interesting fields that are used by the TCP transport protocol. We see how TCP helps control how much data is transferred per segment, make sure there are no erro…
ICMP Protocol - Part 6: Redirect Messages
The ICMP - Redirect Message is always sent from a gateway to the host and the example below will illustrate when this is used.
Putting it simply (before we have a look at the example) the ICMP - Red…
Complete Guide to Nexus Checkpoint & Rollback Fea…
The Cisco NX-OS checkpoint feature provides the capability to capture at any time a snapshot (backup) of the Cisco Nexus configuration before making any changes. The captured configura…
Linux BIND DNS - Part 5: Configure Secondary (Sla…
Setting up a Secondary (or Slave) DNS sever is much easier than you might think. All the hard work is done when you setup the Master DNS server by creating your database zone files and configuring th…
Introduction to Routing Protocols
Distance Vector, Link State RIP, IGRP, EIGRP, OSPF
Routing protocols were created for routers. These protocols have been designed to allow the exchange of routing tables, or known networks, betwee…
The IEEE 802.3 Frame Format
The following is a description of the Ethernet Frame Format described in the IEEE 802.3 Specification. The 802.3 Specification defines a 14 byte Data Link Header followed by a Logical Link Control He…
Troubleshooting techniques for Fast Ethernet
This page will primarily discuss problems unique to Fast Ethernet.
The Collision Domain
Incompatible Ethernet Jabber
Auto-negotiation Priorities And Alternatives
Incompatible Cabling Specificat…
Transmission Control Protocol - Part 4: In-Depth…
This article is an introduction to the 7-page TCP Header analysis section that follows. We briefly view each section of the TCP Header and then move on to its analysis using detailed colourful diagra…
Configuring Cisco Site to Site IPSec VPN with Dyn…
This article serves as an extension to our popular Cisco VPN topics covered here on Firewall.cx. While we’ve covered Site to Site IPSec VPN Tunnel Between Cisco Routers (using static public IP addres…
Understanding, Administering Linux Groups and Use…
In a multi-user environment like Linux, every file is owned by a user and a group. There can be others as well who may be allowed to work with the file. What this means is, as a user, you have all th…
Linux BIND DNS - Part 6: Linux BIND - DNS Caching
In the previous articles, we spoke about the Internet Domain Hierarchy and explained how the ROOT servers are the DNS servers, which contain all the information about authoritative DNS servers the do…
Configuring Linux to Act as a Firewall - Linux IP…
What exactly is a firewall? As in the non-computer world, a firewall acts as a physical barrier to prevent fires from spreading. In the computer world too, the firewall acts in a similar manner, only…
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