Understanding the Extendable Option in IP NAT

[friesen.s4]

Hallo, i can not understand, what do the option "extendable" in this config:

ip nat inside source static tcp 192.1.1.15 5101 172.30.30.1 5101 extendable

ip nat inside source static tcp 192.1.1.10 5102 172.30.30.1 5102 extendable

www.cisco.com:

The extendable keyword allows the user to configure several ambiguous static translations, where an ambiguous translations are translations with the same local or global address.

ip nat inside source static <localaddr> <globaladdr> extendable

Do i have the option "extendable" because of 2 static nat policies with the same global address (172.30.30.1) ?

Thank  You!

[cadet alain]

Hi,

you don't need it here as you have 2 different ports for each translation.

It should be used if you had two links on which you were doing the same static PAT like this for example:

ip nat inside source static tcp 192.1.15 5101 172.30.30.1 5101 extendable

ip nat inside source static tcp 192.1.15 5101 172.30.30.2 5101 extendable

Regards

Alain

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[friesen.s4]

Hallo Alain,

thank you for your Answer!

But i configured on Packet Tracer 2 NAT Policies with the same static PAT:

ip nat inside source static tcp 10.10.10.10  5101  11.11.11.1 5101

ip nat inside source static tcp 10.10.10.15  5101 11.11.11.1 5101

Packet Tracer don't show, that is wrong.

sh run show:

ip nat inside source static tcp 10.10.10.10  5101  11.11.11.1 5101

ip nat inside source static tcp 10.10.10.15  5101  11.11.11.1 5101

Is it Bug of  Packet Tracer?

[cadet alain]

Hi,

PT is not a real platform and the extendable keyword is not available.

Regards

Alain

Don't forget to rate helpful posts.

[rgreville666]

I know this is over a year old now.. but you need to clear your translations.. "clear ip nat trans * " then re-test