Vpn tunnel Asa 5505 to fortigate 60c

Hi nanog,

I have a fortigate 60c connecting a vpn tunnel to an asa 5505. I have the connection setup, but it will not connect because unfortunately the isp at the fortigate end decided to give us a 192.168.13/24 address. Now what I'd like to know is if there is any way to get this vpn connection to work through a pat connection until the isp resolves this issue?

Thank you for any help.


What is the public peer address on the ISP end?

Almost all firewalls support NAT-T, which allows for using a private IP
address on the "outside" of the firewall (which is translated to a
routable public IP address before it gets on the Internet). You will need
UDP 500 (for IKE) and UDP 4500 (for IPsec NAT-T) open, so no devices
between the firewalls can block those ports. I know the ASA supports
this, because I have setup customers with "private" IP addresses on their
ASAs in certain circumstances. I'm not familiar enough with the Fortinet
equipment, but you may need to turn on a NAT-T feature.


Fred Reimer