Well, if you are new to fact that Cisco routers can communicate with Radius servers; then that most likely means, you are new to the Cisco IOS "Global" configuration command called "aaa new-model".

Network administrators (like you) use the "aaa new-model" command to enable the Authentication, Authorization, and Accounting (AAA) access control model on a Cisco router. In other words, the "aaa new-model" command is used to "Globally" enable a Cisco router for Authentication, Authorization, and Accounting or AAA.

Below is an example of using the command:

Example:

Router>enable

Router#configure terminal

Router(config)#aaa new-model

Router(config)#end

Router#

As you can see, it's a very simple command to use; because it doesn't require the use of arguments or keywords.

Now, let's say you've already used the "aaa new-model" command to enable Authentication, Authorization, and Accounting (AAA) on a Cisco router and now you want to disable it; well, to perform that task, all you need to do is type the word "no" in front of the command like you see below.

Syntax: Router(config)#no aaa new-model

And, just in case if you were wondering, Cisco routers by default are not enabled for Authentication, Authorization, and Accounting (AAA), you have to enable them.

I hope this article was very informative and helped you quickly understand the usage of the "aaa new-model"command. If you need to learn more about the command; I suggest you visit my website, were you'll find the latest information regarding Cisco IPv6 Design and Implementation Techniques.

I wrote this article because lately I've been receiving a lot of emails from IPv6 enthusiasts asking me the question "How do I convert Hexadecimal to Decimal without using a calculator?"

Now, although the procedure may sound hard to perform, it's rather easy to do; all you have to do is perform the following steps:

Steps:

1. Locate the "last digit" of the hexadecimal number that you want to convert. (the last digit of a hexadecimal number is the digit that is farthest to the right).

2. Once, you have identified the last digit; you will then multiply the "last digit" with (16^0). In other words, in step number two; you are going to multiply the value of the "last digit" with (16 to the power of zero).

Example: "last digit value" x (16^0) = "last digit value"

Note, that the power of 0 of any number is always 1.

Once, you have performed the formula on the last digit, write down the result; and then move on to the previous digit on the (your) left.

3. Each time you move on to a previous digit, you'll need to increase the power (16^X) of the formula by 1 before performing the formula on that digit.

4. Simply perform the formula (digit value x (16^X) on all of the remaining digits until all digit results have been written down.

5. Then add (sum) all of the written down (stored) results together to get the final answer number.

Here's an example: We are converting the HEXADECIMAL number FB8 to DECIMAL(the number 8 is the "last digit")

1. 8 x (16^0) = 8
2. B x (16^1) = 176
3. F x (16^2) = 3840
4. 8 + 176 + 3840 = 4024

So, the decimal equivalent of the hexadecimal number FB8 is 4,024.

Here's another example: We are converting the HEXADECIMAL number 7747 to DECIMAL (the number 7 is the "last digit")

1. 7 x (16^0) = 7
2. 4 x (16^1) = 64
3. 7 x (16^2) = 1792
4. 7 x (16^3) = 28672
5. 7 + 64 + 1792 + 28672 = 30535

So, the decimal equivalent of the hexadecimal number 7747 is 30,535.

Below is a quick reference of the powers of 16:

16^0 = 1
16^1 = 16
16^2 = 256
16^3 = 4096
16^4 = 65536
16^5 = 1048576

I invite you to visit my website were you'll find the latest information regarding Cisco IPv6 Design and Implementation Techniques.

To your success,

Charles Ross, CCNP #CSCO10444244 is the owner of Ittechtips.com; where you'll find free comprehensive information and videos about IPv6 technology and how it works with Cisco Systems technology.

Well, if you are new to the IT networking field, you probably feel it's quite fascinating or it's very overwhelming, trying to understand all of the different Interior Gateway Protocols (IGP's) that can be used to route packet information within a network.

If you are feeling overwhelmed by it all don't worry, you're not alone; I felt the same way. That's why I wrote this article to help you quickly understand the major differences between EIGRPv6 and EIGRPv4.

In a nutshell, the overall operation and features of EIGRPv6 are still the same as they are in EIGRPv4. But, EIGRPv6 does differ from EIGRPv4 in the following ways:

* EIGRPv6 is configured (enabled) directly on Cisco router's interfaces; this means EIGRPv6 can be configured (enabled) on a router's interface, without having to configure (assign) a Global IPv6 address on the interface and without using the "network" command while the router is in router configuration mode.

* Also, when configuring (enabling) EIGRPv6 on a Cisco router, the EIGRP routing process must be configured (assigned) with a "router-id" (by using the router configuration command "router-id"); if a "router-id" is not configured (assigned) the EIGRPv6 routing process will not start.

* The EIGRPv6 routing process also uses a "shutdown" feature; meaning an EIGRPv6 routing process will not start until the routing process has been placed into "no shutdown" mode. (by, typing the "no shutdown" command while the router is in router configuration mode)

* Also, on Passive Interfaces; EIGRPv6 is not required to be configured.

* Lastly, EIGRPv6 use the router configuration command "distribute-list prefix-list" to perform route filtering; and when configuring route filtering the "route-map" command is not supported.

I invite you to visit my website were you'll find the latest information regarding Cisco IPv6 Design and Implementation Techniques.