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PAT/overload from outside to inside

Unanswered Question
Oct 16th, 2007
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I have host using a private internal IP that will only talk to machines on the same private IP. I need to have public IPs talk to this machine. I have a PIX that uses the same private IP subnet on its inside interface. What I would like to do is a PAT/overload scenario in reverse where multiple outside hosts will talk to the inside host using one IP from the private subnet. I think I have seen this mentioned somewhere but can't find it. One caveat is that the PIX must also do PAT/overload for internal hosts going out to the Internet at the same time. Is this possible?



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Overall Rating: 4 (2 ratings)
sundar.palaniappan Tue, 10/16/2007 - 15:47
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You can do this with static, NAT and ACL to address both requirements.

Here's a configuration example that you can use to build your configuration.

Inside Web Host that needs to be accessed from Outside:

int e0

nameif outside

security-level 0

ip add

int e1

nameif inside

security-level 100

ip add

access-group acl_outside in interface outside

access-list acl_outside permit tcp any host eq www

nat (inside) 1

global (outside) 1 interface

static (inside,outside) interface tcp 80



Jon Marshall Tue, 10/16/2007 - 19:41
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Hi Diego

Sundar has covered most of this but to PAT all outside addresses

access-list PATIN permit ip any host

(Note, i'm using Sundar's IP addressing and you might want to tie access down to the particular tcp/udp ports)

nat (outside) 2 access-list PATIN outside

global (inside) 2 interface



DIEGO ALONSO Thu, 10/18/2007 - 08:25
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Thanks guys. I will give this a shot and let you know what happens.


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