Recent posts

Get Involved - Forums

April 18, 2010

Whether you are are a seasoned Cisco professional or just starting out, one of the best sources of information you will find (apart from this blog :P) are internet forums. You will be amazed at just how much you can learn from them, and, if you have the time, how much you can teach others too. It is also a great place to “network” (excuse the pu...

CBAC in Action, Part 2

April 18, 2010

In my previous CBAC post I covered how to deny all external traffic unless it is in response to a request someone on the LAN has made, e.g If you send a ping, CBAC will allow the ping reply traffic to come through the firewall. However, this situation may not be ideal for everyone. What if you wanted to allow one or more protocols in to your ne...

CBAC in Action, Part 1

April 18, 2010

In a previous post I talked about CBAC and a few of the ways in which it, in conjunction with NBAR can be used to secure your network. Today I will create a lab to show you how to put it to good use. In this lab we have four routers, R1, R2, R3 and R4 (very original I know). Here are there designations: R1 = Local LAN - Your network R2 = ...

CBAC Firewall

April 17, 2010

In my previous post I mentioned the Cisco IOS firewall feature known as CBAC (Context-Based Access Control). Today I will describe it in more detail and explain how you can use it to increase the security of your network. As you may know, a firewall is used to protect your network from the outside world and all of the nasty hackers out there. W...

NBAR and its Many Uses

April 16, 2010

NBAR, also known as Network Based Application Recognition is an invaluable tool that many people do not know exists or simply just don’t use it enough. As the name suggests, NBAR reads packets that flow through a router and “recognises” the types of applications that are sending the packets. Examples of applications that can be recognised inclu...