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swmar
swmar
New Member
November 5, 2016
Question

fortigate disable nat option

  • November 5, 2016
  • 1 reply
  • 26136 views

Dears,

I have fortigate 200d and i want to disable nat option once i create the firewall policy.

could you please advise what is the other steps that i need to configure in case i disabled the nat option from the policy.

when i enable the nat mode in the policy, the connectivity is ok, but when i disabled it i lost the connectivity, i want to keep the source ip without natting. could you please advise about this 

 

Best Regards,

 

1 reply

rwpatterson
rwpatterson
New Member
November 5, 2016

This is a very general question. 2 questions to you:

1) What direction is traffic flowing in this policy?

2) Is this policy connected to the Internet from a private address?

swmar
swmarAuthor
New Member
November 5, 2016

Thanks for your reply, the direction from internal to wan 1.

and it is private network to the internet.

 

 

Best Regards,

rwpatterson
rwpatterson
New Member
November 5, 2016

If that is the case, then you need to have NAT enabled. Your ISP will drop all connections to the Internet with private IP addresses. You have to provide a routable, public IP address if you want your traffic to be present outside your walls. The only way you can do that is to have your own subnet(s), or to NAT your traffic to the IP address that your ISP provides you. (That is if they give you a public. Some only provide private IP addresses on a transit network to you.)

 

See the link for a definition/list of private IP address ranges

 

https://tools.ietf.org/html/rfc1918

 

There is a newer one, but I don't recall the RFC number.

 

The latest is here:

 

https://tools.ietf.org/html/rfc5735

 

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