Not Found

NAT or Network Address Translation is a key function required in every organisations network.
Since all organisation use RFC 1918 IP addressing, and these IP addresses are not allowed to exist on the internet, before we send packets to the internet we need to translate the internal IP address into a useable public IP address.
There are [...]

One of the first and most important things to configure on any Cisco device after allowing telnet or SSH, is to restrict who is allowed to access the device. Of course having a password on the lines is the first step but if telnet is the method of communication, all passwords will be sent over [...]

Before looking into the configuration of ACL (Access Control Lists), it’s important to get some of the concepts and understanding of how they work and what they are used for.
Firstly, most people believe that ACL’s are used purely for denying or allowing traffic, although this is certainly one of the functions of a ACL it [...]

In order for 2 VLANS to be able to communicate, the traffic must be routed. This can be done either by a multi-layer switch which will have routing capabilities, or the packets can be routed by a router.
 
As an example, I have 2 VLANS, VLAN 10 and VLAN 20 which have subnets 10.0.10.0/24 and 10.0.20.0/24 [...]

VTP (VLAN Trunking protocol) is a protocol used to replicate the VLAN information across switches, however there are a few things that must be made clear…
 
1/ VLAN information will only be sent on trunk ports
2/ Only the VLAN identity is replicated, NOT which ports are configured to use that VLAN!
3/ Maintains database consistency through a [...]

A VLAN is a Virtual LAN which allows us to logically separate computers on our network.
 
In previous years, an office would have a physical switch or hub in each office, and offices were structured around the job function. In other words, all sales people would be in the same office and would all be connected [...]

In order to control what machines are plugged into your network, Cisco introduced the “switchport port-security” command.
 
In this tutorial I’m going to explain how to use this command, and different options available using it.
 
Below is the breakdown of the commands I used in the live demo, and an explanation of each.
 
 
AOIP.ORG_Switch# terminal monitor
Since I was [...]

Once VLANS have been defined on a switch and you have placed ports into their corresponding VLANS, traffic is limited to remain inside it’s Virtual LAN. The only way for traffic to leave the switch, is to have it sent on a port that is in the same VLAN as its source, or sent over [...]

Almost 100% of Cisco switches will have a 50 second delay on a port before it goes live. What this means, is that when you plug a new device into a switch such as a PC, there will be a 50 second delay before the port will become active and the PC will be able [...]

The configuration of an IP address on a switch is slightly different from a router.
On a router we configure the IP address on the physical interface, however on a switch the physical interfaces are running at Layer 2 and hence don’t have IP addresses configured on them.
 
Even though a switch does not need an IP [...]