Many to One NAT

[michael.zammit]

Hi Guys,

I have a requirement where I need to NAT the destination IP address of traffic that is from two different sources.

For example, If either 172.31.50.1 or 172.31.50.2 send traffic to the destination 172.31.164.48, I require the destination IP to be NAT'd to 172.16.4.1.

What's the best way of going about this?  I've tried several different NAT setup's but recieve a Cisco error message that the IP address I'm trying to NAT to is already mapped to another IP.

Any help would be greatly appreciated.

Thanks.

[Dennis Mink]

What device is this on? ASA? Router?

what you require is destination NAT.  If its a router, check this link out

http://www.cisco.com/en/US/tech/tk648/tk361/technologies_configuration_example09186a0080093f8e.shtml

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[michael.zammit]

Thanks for your reply.

Yep, it is for a router.

I've had a look at the above link but am I little unsure of it.  WIll it allow me to specifically set multiple destination IP's to nat to the same address?  How would this be configured?

[blau grana · Accepted solution]

Hello Michael,

Maybe I missed something, but to me it seems that you just need simple static NAT.

For example, If either 172.31.50.1 or 172.31.50.2 send traffic to the destination 172.31.164.48, I require the destination IP to be NAT'd to 172.16.4.1.

ip nat inside source static 172.16.4.1 172.31.164.48

172.31.50.0/24 ---- network ---- router ---- 172.16.4.0/24

router config

int fa0/0

  descript interface toward network

  ip add 172.31.164.48 255.255.255.0

  ip nat outside

int fa0/1

  descript interface subnet 172.16.4.0/24

  ip add 172.16.4.254 255.255.255.0

  ip nat inside

ip nat inside source static 172.16.4.1 172.31.164.48

All traffic which arrive on interface (172.34.164.48) will be forwarded to IP 172.16.4.1 [destination IP will be translated]

Best Regards

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