FortiGate Administration Guide - FirewallShop.com

Configuring virtual IPs
Firewall Virtual IP
Method
Port forwarding
Protocol
External Service
Port
Map to Port
Real Servers
If you select Server Load Balance, you can select one of the following
load balancing methods.
• Static: The traffic load is spread evenly across all servers, no
additional server is required.
• Round Robin: Directs request to the next server, and treats all
servers as equals regardless of response time or number of
connections. Dead servers or non responsive servers are avoided.
A separate server is required.
• Weighted: Servers with a higher weight value will receive a larger
percentage of connections. Set the server weight when adding a
server.
Select to add a port forwarding virtual IP.
Select the protocol (TCP or UDP) that you want the forwarded packets
to use.
Enter the external service port number for which you want to configure
port forwarding.
Enter the port number on the destination network to which the
external port number is mapped.
You can also enter a port number range to forward packets to multiple
ports on the destination network.
For a static NAT virtual IP, if you add a map to port range the FortiGate
unit calculates the external port number range and adds the port
number range to the External Service port field.
If you select Server Load Balancing for the VIP type, enter the real
server IP addresses. At least one IP address is required and you can
enter up to eight addresses.
To enter a server IP address, select Add under Real Servers and
enter the following information:
IP: Enter the IP address of the server.
Port: If you enable port forwarding, enter the port number on the
destination network to which the external port number is mapped.
Dead interval: The interval of time that a connection can remain idle
before it is dropped. A range of 10-255 seconds can be used.
Wake interval: The interval of time the connection will try to detect a
server before giving up. A range of 10-255 seconds can be used.
Weight: Determines the weight value of a specific server. The high
the weight value, the higher the percentage of connections the server
will handle. A range of 1-255 can be used.
Health Check: Enable this option to use ping detection to check the
status of the server before forwarding the session.
Adding a static NAT virtual IP for a single IP address
The IP address 192.168.37.4 on the Internet is mapped to 10.10.10.42 on a
private network. Attempts to communicate with 192.168.37.4 from the Internet are
translated and sent to 10.10.10.42 by the FortiGate unit. The computers on the
Internet are unaware of this translation and see a single computer at 192.168.37.4
rather than a FortiGate unit with a private network behind it.
FortiGate Version 3.0 MR5 Administration Guide
310 01-30005-0203-20070830