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michael_fees
michael_fees
New Member
August 28, 2018
Question

VPN (IPSec or SSL) Client Access to a Fortigate 500D behind a provider network with NAT

  • August 28, 2018
  • 1 reply
  • 2427 views

Hi, We changed the dedicated line to a dedicated line behind a provider network. Our outside-Interface has a number like 198.18.152.2/28. The external address of the VPN Endpoint must be 212.211.112.160/28. Inside SSL-VPN configuration that means: I can only configure the outside interface as the endpoint for VPN. So in SSL-VPN Settings I can't change [link=https://198.18.152.2<port>]from [link]https://198.18.152.2:<port>[/link][/link] to https://212.211.112.160:<port>. And inside the IPSec Tunnels I can bind only outside interface. The ISAKMP are received at 212.211.112.160 but IPSec is mapped to the outside 198.18.152.2 There is a virtual IP static NAT address mapping external IP address 198.18.152.2 to mapped IP address 212.211.112.160 Has anyone a good suggesstion? Thank you in advance. Michael

1 reply

Toshi_Esumi
SuperUser
Toshi_Esumi
SuperUser
August 28, 2018

Only way I can see is:

[SSL VPN]

- get the <port> forwarded at the vendor's NAT device to 198.18.152.2 (it's a public IP though)

- the client side uses 212.211.112.160:<port>

[IPsec]

- get UDP 500, 4500 forwarded at the vendor's NAT device to 198.18.152.2

- get ESP protocol passed through the NAT device

 

Otherwise, they wouldn't work. If 198.18.152.2 is actually a public IP reachable from the internet, asking vendor not to NAT is the best option.

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