Network Address Translation – Cisco Routers

In this lecture we will discuss the definition of the following terms:

• Inside Local

• Inside Global

• Outside Local

• Outside Global

Questions to ask yourself after watching this video?

• What do the terms "Inside" vs "Outside" refer to?

• What do the terms "Local" vs " Global" refer to?

• What do each of the four combined terms refer to in so far as Network Address Translation?

In this video we describe the Topology we will be using to configure and verify every type of NAT translation on a Cisco Router. I'll explain the lay out of all the windows, and how we're going to be showing you every packet BEFORE translation and AFTER translation. This will show you EXACTLY what the Cisco Router is doing.

In this command we look at how to designate NAT interfaces on a Cisco router. We'll learn where and when to use the commands ip nat inside and ip nat outside

In this video we will be Configuring and Verifying Static NAT on a Cisco Router.

After watching this lesson you will be able to answer these questions:

• What is the Syntax to configure a Static NAT?

• What does each part of the Syntax in the Static NAT command mean?

• What command can you use to verify the translations that are occurring through your Cisco Router?

• BONUS:  What is an ICMP Sequence number and why is it used?

In this lesson we will be Configuring and Verifying a Static PAT on a Cisco Router.

After watching this video you will be able to answer these questions:

• How is the Static PAT command different/similar to the Static NAT command?

• What are some reasons to configure a Static PAT using a Standard port internally and a Non-Standard port externally?

• What are some reasons to configure a Static PAT using a Non-Standard port internally and a Standard port externally?

• What command would you use to verify the operation of a Static PAT?

• What does the "extendable" argument enable?

• BONUS: What does it imply in so far as IP address conservation?

• What does "hole punching" mean?

• How does the Router behave when combining Static PAT's with a Static NAT?

• In what situations would you want to combine some Static PAT's with a Static NAT?

  
  

In this lesson we will be Configuring and Verifying Dynamic PAT on a Cisco Router.

After watching this video you will be able to answer these questions:

• What are the three parts to a Dynamic PAT configuration?

• What does the "overload" argument do?

• What is the purpose of the "netmask" or "prefix-length" argument in the "ip nat pool" command?

• What is a Cisco Router's behavior with Source Ports passing through a Dynamic PAT?

• Is a Dynamic PAT Unidirectional or Bidirectional? Why?

• BONUS: What could I configure if I wanted to allow the inbound TCP/443 connection back through my Dynamic PAT?

In this lesson we will be Configuring and Verifying Dynamic NAT on a Cisco Router.

After watching this video you will be able to answer these questions:

• What are the three parts to a Dynamic NAT configuration?

• How is a Dynamic NAT configuration different from a Dynamic PAT configuration?

• Is a Dynamic NAT unidirectional or bidirectional?

• Does a Dynamic NAT allow multiple internal hosts to share a single Global IP?

• What command can you use to verify how many addresses have been allocated or how many allocations were missed in your NAT pool?

• What command can you use to verify the duration of a Dynamic NAT allocated?

In this lesson we will be Configuring and Verifying a Policy Dynamic PAT on a Cisco Router. This is Part 1 of 2 in the lesson covering Policy NAT.

After watching this video you will be able to answer these questions:

• How is a Policy NAT different from the other NATs we configured?

• How do you configure a Policy Dynamic PAT/NAT (compared to a regular Dynamic PAT/NAT)?

• What consideration to you have to make in so far as the order of the "ip nat" commands when combining a Dynamic PAT with Policy Dynamic PAT?

In this lesson we will be Configuring and Verifying a Policy Static NAT/PAT on a Cisco Router. This is Part 2 of 2 in the lesson covering Policy NAT.

After watching this video you will be able to answer these questions:

• What are the three parts required to configuring a Policy Static NAT or PAT?

• How do you verify the operation of a Policy Static NAT or PAT?

In this lesson we will be Configuring and Verifying Twice NATs on a Cisco Router.

After watching this video you will be able to answer these questions:

• How is a Twice NAT different from every other type of NAT we discussed?

• How is a Twice NAT different from a Policy NAT?

• What translation methods exist for the Outside host on a Cisco Router?

• How do you configure a Twice NAT on a Cisco Router?