Access-Lists
So we have already looked at all 3 possible NAT configurations, however there is one more trick that is always useful to know. How to overload a Static NAT. Let’s assume the following for this example: * We have 2 public IP addresses (192.168.1.1 & 192.168.
Access-Lists
PAT (Port Address Translation) is by far the most common implementation of NAT, and if you have an ADSL router at home there is a 100% chance you are using it. PAT or otherwise known as NAT overload, allows you to translate IP addresses in a many-to-one method. In my
Access-Lists
In my last post Configuring Static NAT on Cisco Routers we saw how you can translate 1 IP address into another single IP address. This tutorial will cover how to translate many IP addresses into many IP addresses, otherwise referred to as many-to-many translation. Dynamic NAT allows us to translate
CCNA (ICND2)
In my previous post on NAT, I explained the difference between the 3 different types of NAT that can be configured. In this tutorial I’m going to cover the configuration steps to configure static NAT. Static NAT is a one-to-one mapping. It allows us to translate a single IP
CCNA (ICND2)
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
Access-Lists
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 and often configured correctly. The unfortunate thing about password
Access-Lists
Access-lists are the cornerstone of security in networking. They are used on Routers, Switches and Firewalls and are often a challenge to understand when first starting your career in networking. Before we dive into the configuration of access-lists, or otherwise known as ACL’s (Access Control Lists), it’s important
BCMSN
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 (Router on a Stick) As an example, I have 2 VLANS, VLAN
BCMSN
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
BCMSN
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
BCMSN
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
BCMSN
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