DescriptionThis article explains how to configure area number greater than 255 on the FortiGate OSPF setting to match that of Cisco.
The area ID in OSPF is represented in a dotted decimal format, similar to an IP address. While Cisco routers allow a single decimal value for configuring area, a FortiGate requires the area to be configured in a dotted decimal format.
ScopeFortiOS 4.0, 5.0, 5.2
SolutionThe decimal area that is configured on the Cisco will have to be converted into a dotted decimal format and then used on the FortiGate.
Example 1:
Area number configured on the Cisco 256
Corresponding dotted decimal format for FortiGate is: 0.0.1.0
Example 2:
Area number configured on Cisco 257
Corresponding dotted decimal format for FortiGate is: 0.0.1.1
Using the sniffer:
The other way, in case you do not want a conversion would be to run a sniffer on proto 89 and look at the OSPF header. The command is:
diagnose sniffer packet "proto 89" 6 0 a
Once the packets are captured, convert it using help from the related KB article 'How to import Diag Sniff Packet data to WireShark - Ethereal application'.
An example is shown below:
Related Articles
Technical Note: How to import 'diagnose sniffer packet' data to WireShark - Ethereal application