NAT in Cisco ASA 5585 X ios 8.2(5)

[sarb_sharmin]

Hello there!

I am facing a strange problem regarding Natting in Cisco ASA 5585 X ios 8.2 (5).

When I configure dunamic NAT like

global (outside) 1 180.149.31.1-180.149.31.249 netmask 255.255.255.0

nat (inside) 1 172.17.160.0 255.255.254.0

whole inside IP(172.17.160.0 255.255.254.0) is natted through one public IP(180.149.31.1) . Please help me to resolve the issue.

[Jouni Forss]

Hi,

The NAT should not really behave like that.

Your NAT Pool seems to be smaller than the source network though which would seem like a bad idea unless you have a another ID1 "global" statement that defines a PAT IP address?

Could you share the output of

show run global

show run nat

You can use the "packet-tracer" command also to view which translation is hit

packet-tracer input inside tcp 172.17.160.100 12345 8.8.8.8 80

If all the configurations are correct then it would seem like a bug. I have never run into such then again I have not configured NAT pools that many times. Mainly for the reason that very few customer has the need for one nowadays or enough public IP addresses use an actual NAT Pool.

- Jouni