How to verify the contents of the routing table (in NAT mode)

When you have some connectivity, or possibly none at all a good place to look for information is the routing table. The routing table is where all the currently used routes are stored for both static and dynamic protocols. If a route is in the routing table, it saves the time and resources of a lookup. If a route is not used for a while and a new route needs to be added, the oldest least used route is bumped if the routing table is full. This ensures the most recently used routes stay in the table. If your FortiGate unit is in Transparent mode, you are unable to perform this step.

If the FortiGate is running in NAT mode, verify that all desired routes are in the routing table: local subnets, default routes, specific static routes, and dynamic routing protocols.

To check the routing table in the web-based manager, use the Routing Monitor by going to Router > Monitor > Routing Monitor.

In the CLI, use the command get router info routing-table all. Sample output:

FGT# get router info routing-table all

Codes:

K – kernel, C – connected, S – static, R – RIP, B – BGP O – OSPF, IA – OSPF inter area

N1 – OSPF NSSA external type 1, N2 – OSPF NSSA external type 2

E1 – OSPF external type 1, E2 – OSPF external type 2

i – IS-IS, L1 – IS-IS level-1, L2 – IS-IS level-2, ia – IS-IS inter area

* – candidate default

S* 0.0.0.0/0 [10/0] via 172.20.120.2, wan1

C 10.31.101.0/24 is directly connected, internal

C 172.20.120.0/24 is directly connected, wan1