NAT Configuration on a Cisco Router

This is a tutorial that shows how to configure network address translation (NAT) on a Cisco router. For additional videos and white papers from West Gate Networks, please visit http://www.westgatenetworks.com

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• Cisco
• router
• configuration
• NAT
• cisco
• tutorial
• training

[kb8zxe]

Nice example, but, how would you do this with a dynamic ip address. I have a network consisting of a few 1601's (using VLSM) and I would like to add internet to them. I have a dsl modem that will hand out a public IP but it always changes. All the NAT example that I see use a fixed IP, how would it be different for dynamic? Thanks...

[westgatenetworks]

If your 1601's are running IOS 12.1T or above, they should have a command to dynamically assign an IP to an interface. So instead of assigning a static IP on int fa0/1, you just do these commands:

int fa0/1

ip address dhcp

Your Interface will then pick up a dynamic address from your ISP and NAT will run without problems even when the interface address changes. I hope this helps!

[Iwasblocked]

In your topology, you have fa0/1 connected to the cloud... I thought you can only use serial interfaces to a cloud...pls help...

[westgatenetworks]

The assumption is that there is a DSL or cable modem attached to the int fa0/1 interface.

[ITSystemsAdmin]

NICE VIDEO CHECK DHCP 2008 R2!

[ssreckov]

idiot

[JoeyTribiane]

@Awantg eeewps...I looked at this for about 3 seconds...I am sooo used to seeing 192.168.0.0/16, plus I just got done training a CCNA bootcamp, and I had to go back over CIDR and their masks (A=/8, B=/12, C=/16)

[VictorButny]

Great video, i learned the part with "access-list" now! Thanks...:)

[enyawix]

What is "ip virtual-reassembly"? My router auto inserts this line on my interfaces.

[rickput]

ok i'm not a techy guy but when i play my game online and try to create a server, it says i'm on a private network and others wont be able to join me, is there an "easy" way to fix this?

[thimmarayasamy]

thanks



[asmae63]

thanks

[PsylencedMike]

@Awantg

You can use any wildcard mask in case of NATting for non-connected networks, or multiple networks spanning multiple interfaces.

Example:

The following could all be allowed through the NAT process using wildcard 192.168.0.0/16:

Fa0/0: 192.168.10.0/24

Fa0/1: 192.168.20.0/24

Fa1/1: 192.168.210.0/24

[Awantg]

@JoeyTribiane

why do you say that?... 3rd octect is network in this case..