About virtual IPs
Virtual IP (VIP) addresses enable users from outside a private network to access services inside that network. Under normal circumstances, this is not possible because Internet routers generally do not connect to private IP addresses. For example, a user from the Internet is not able to access an internal page on a company network. However, the FortiGate unit can be configured to allow an employee of a company to access an internal web page on a private network from the Internet.
FortiGate must be in NAT/Route mode to add VIPs.
Creating a static VIP
Static NAT virtual IP for a single IP address is the simplest virtual IP configuration. A single IP address on one network is mapped to another IP address on a second network. The FortiGate unit connects the two networks and allows communication between them.
To create a static VIP
- Go to Firewall > Virtual IP.
- Select Create New.
- Enter a name for the Virtual IP you will create.
- Select the interface the new Virtual IP will be entering from.
- Select Static NAT.
- Enter the address for the virtual IP in External IP Address/Range.
This is the address visible to users outside the network. - Enter the internal IP address in Map to IP Address/Range.
This address is invisible to users outside the network. It is the address for the page linked to the external IP. - Select OK
Creating a VIP with port forwarding
With port forwarding, a port or a range of ports on computers outside the network can be linked to a port or range of ports inside the network.
To create a VIP with port forwarding
- Go to Firewall > Virtual IP.
- Select Create New.
- Enter a name for the Virtual IP you will create.
- Select the interface the new Virtual IP will be entering from.
- Select Port Forwarding.
- Enter the address for the virtual IP in External IP Address/Range.
This is the address visible to users outside the network. - Enter the internal IP address in Map to IP Address/Range.
This address is invisible to users outside the network. It is the address for the page linked to the external IP. - Select OK
Configuring the Firewall
You must create a firewall service and a firewall policy for the Virtual IP address to function, and to allow traffic to flow between the VIP and the network.
To create a firewall service
- Go to Firewall > Service > Custom.
- Select Create New
- Enter a name for the new service.
- Select the protocol for the new VIP.
- Leave the default settings for Source Port.
- Enter the destination port numbers for the new service.
- Select OK.
To create a firewall policy
- Go to Firewall > Policy.
- Select Create New
- Select the external port connected to the internet for Source Interface/Zone.
- Select all for Source Address Name.
- Select the internal port connected to the network for Destination Interface/Zone.
- Select the virtual IP you created for Destination Address Name.
- Select the service you just created from the Service options.
- Select OK.