MicroNugget: What is Network Address Translation?

In this video, Keith Barker covers NAT, why it's necessary, and its relationship to PAT. Obviously a local network can assign addresses however it wants to, but somehow traffic headed for the Internet has to get a global address. Naturally, NAT's how it happens.

Speaking generally, an IP address isn't really anything more than a street name and a house number — useful if you're in the same area, but useless if you don't know what city, state or country the street is in. When you're on a local network, that's usually no problem — but private addresses don't work on the Internet. That's where Network Address Translation comes in.

When a host makes a request that's headed for the Internet, a router substitutes the private address for its own global address, and then when the fulfilled request comes back, the router remembers which host originated the request and untranslates the global address back to private. NAT and PAT are vital for routing and help keep the number of global addresses to a minimum.

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[KeithBarker]

Glad you like the videos. Thank you for the feedback!

Keith

[KeithBarker]

Hello Adam.

Yes, you are absolutely correct! They often use a flavor of NAT called PAT (port address translation) that allows all the IP addresses on the inside be translated to the single IP address that is being used by the router itself.

Cheers,

Keith

[niiodaie]

You are the best Keith....you keep it easy and simple, great JOB man!!!
You + Jeremy rock the Networking World

[KeithBarker]

Hi Manoj-

Thanks for the feedback! I appreciate it.

Keith

[joselevicanasenjo]

Keith, I just came across your channel. I just loved it. It has been very informative, the best!. THe Wireshark demostration is very helpful, and clarified many doubts I had. I dont know if there is another channel that explains networking as well as you do. I am starting to follow you!! Thanks for posting

[cbtnuggets]

He's also working on several full length series for us, currently he's working on one for Network+

[Santosh]

A simple and very informative video for beginners. Thanks a lot.

[Dinodialoo]

you and Jeremy are the best of the best, well done

[VS-wsls]

Helps alot! Im graduating tomorow and NAT is one of the question, I knew NOTHING about it, but now I know how it works pretty well! thanks

[sbentjies]

Thanks for making it simple to understand!

[KeithBarker]

Hello-

2 or more inside clients, sharing the same (single) global address, is PAT.

In answer to your question, yes.

Keith

[ankitdoshi]

Awesome Explanation while covering almost everything...
Thank You Sir
Don't stop with such tutorials in future :P
It helps a lot :)

[johnconnor]

Thank you for your awesome tutorials :)
Could you please help with one question related to NAT configuration.

Should we also configure our OUTSIDE port on a router as a default route (0.0.0.0 0.0.0.0 next_hop_ip)? Otherwise how the router will know that it should use NAT for a certain request of the user

[muhammadlateef]

Keith thanks for sharing very useful information.

Can you please do a short nugget on NAT-T

[lupineye]

Yes! usually home wireless router has PAT and RIP as long as I know.

[Midnight]

thanks a lot for the informative video :)

[vigilantezack]

New sub, looking forward to all Net+ stuff. Thanks a bunch!

[TauterHobo]

Thanks a lot of good information but I do have a when playing games online why does the NAT change to strict for some people?

[jaykb]

Missed the point, why NAT in the first place. Coz we dont have enough ipv4 addresses

[Voodookillers]

this info.... is so basic it makes to much sense, THANK YOU! xD