About NATing

[fb_webuser]

Hi ,I have some questions,Is it true that in the routers we need to install a software for NATing or the routers already have NATing feature by default?

Also do all ASA firewalls have built in NATing and we simply have to enable it?

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Posted by WebUser Fahad Ahmed from Cisco Support Community App

[Christopher Bell]

The ASAs will NAT, just need to configure it. Any Cisco router that I can I can think of should also NAT natively.


Sent from Cisco Technical Support Android App

[Marvin Rhoads · Accepted solution]

All Cisco routers and ASA appliance are able to NAT at the minimum base licensing level.

Some switches may need IP Base if they currently have a LAN base image / license.

[fb_webuser]

Ok Thanks for your reply Sir Marvan,

I have other question, Is NATing also one of the solutions for the Classful IP addressing schemes?

My other question is that do we have to purchase the licensing from Cisco?

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Posted by WebUser Fahad Ahmed from Cisco Support Community App

[fb_webuser]

Also my other question is that by IP base, do you mean Layer 3 switches?

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Posted by WebUser Fahad Ahmed from Cisco Support Community App

[Marvin Rhoads]

You're welcome.

Re NAT and classful / classless addressing - they aren't really directly related in any obvious way.

Re licensing and IP Base - many Cisco switches are sold with various feature sets or licensing levels. Depending on your model and how it was purchased, a license upgrade may have to be purchased to run certain features. To check your licensing level, the "show version" command includes information about the licensed software image in its output.

[fb_webuser]

Sorry Sir, I made a mistake in my question, I meant to say that is NATing also one of the solution for the classful IP addressing scheme as the users on internet are rising so IPV4 address is reducing/exhausted?

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Posted by WebUser Fahad Ahmed from Cisco Support Community App

[Marvin Rhoads]

No those are two different subjects, related only in that they both are about IP addressing.

NAT assists in prolonging the use of address space in that it allows users to use private (RFC 1918) addresses internally and translating them to a smaller pool of public registered addresses when they need to talk to Internet-based systems.

Classless Inter-Domain Routing (CIDR) IP addressing allows one to use variable netmasks (and summarize in advertising or at routing nodes and boundaries) that are other than the 8/16/24 -bit classful masks of Class A, B or C networks.

[fb_webuser]

Thanks for your reply,

Ok, so in way NAT also allows us to use this IPV4 addressing scheme in long period?

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Posted by WebUser Fahad Ahmed from Cisco Support Community App

[fb_webuser]

Sir,can we also do NATing in case of IPV6?

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Posted by WebUser Fahad Ahmed from Cisco Support Community App

[Marvin Rhoads]

Fahad,

While you may NAT IPv6 addresses (IPv6 to IPv6), there is no real need to do so as there is not the scarcity of registered addresses to use as there are with IPv4 ones.

NAT is used with IPv6 primarily as a transition tool - i.e. NAT 6to4 where you have IPv6 on one network and need to communicate to IPv4 on another one.