Chapter 2 Advanced Routing for FortiOS 5.0 : Open Shortest Path First (OSPF) : Basic OSPF example : Configuring OSPF on the FortiGate units : Configuring OSPF on Router3
  
Configuring OSPF on Router3
Router3 is more complex than the other two routers. The interfaces are straightforward, but this router has to import and export routes between OSPF and BGP. That requirement makes Router3 a border router or ASBR. Also Router3 needs a lower cost on its route to encourage all traffic to the Internet to route through it.
In the advanced OSPF options, Redistribute is enabled for Router3. It allows different types of routes, learned outside of OSPF, to be used in OSPF. Different metrics are assigned to these other types of routes to make them more or less preferred to regular OSPF routes.
To configure OSPF on Router3 - web-based manager
1. Go to Router > Dynamic > OSPF.
2. Set Router ID to 10.11.101.2 and select Apply.
3. Expand Advanced Options.
4. In Redistribute, set the following information, and select OK.
Route type
Redistribute
Metric
Connected
Enable
15
Static
Enable
15
RIP
Disable
n/a
BGP
Enable
5
 
 
 
5. In Areas, select Create New, set the following information, and select OK.
Area
0.0.0.0
Type
Regular
Authentication
none
6. In Networks, select Create New, set the following information, and select OK.
IP/Netmask
10.11.0.0/255.255.0.0
Area
0.0.0.0
7. In Interfaces, select Create New, set the following information, and select OK.
Name
Router3-Internal
Interface
port1 (Internal)
IP
0.0.0.0
Authentication
none
Timers (seconds)
 
Hello Interval
10
Dead Interval
40
8. In Interfaces, select Create New, set the following information, and select OK.
Name
Router3-Internal2
Interface
port2 (Internal2)
IP
0.0.0.0
Authentication
none
Timers (seconds)
 
Hello Interval
10
Dead Interval
40
 
9. In Interfaces, select Create New, set the following information, and select OK.
Name
Router3-ISP-BGP
Interface
port3 (ISP-BGP)
IP
0.0.0.0
Authentication
none
Cost
2
Timers (seconds)
 
Hello Interval
20
Dead Interval
80
10. Using the CLI, enter the following commands to set the priority for the Router3‑Internal OSPF interface to ensure this interface will become the BDR.
config router ospf
config ospf-interface
edit Router3-Internal
set priority 250
next
end
To configure OSPF on Router3 - CLI
config router ospf
set router-id 10.11.102.3
config area
edit 0.0.0.0
next
end
config network
edit 1
set prefix 10.11.0.0/255.255.255.0
next
edit 2
set prefix 172.20.120.0/255.255.255.0
next
end
config ospf-interface
edit "Router3-Internal"
set interface "port1"
set priority 255
next
edit "Router3-External"
set interface "port2"
next
edit “Router3-ISP-BGP”
set interface “port3”
set cost 2
next
end
end