| Description | This article describes the FortiOS routing logic that applies when multiple default routes through different routing protocols are used. |
| Scope | FortiOS 5.x, 6.x and 7.x. |
| Solution |
The following diagram illustrates a typical topology in which a client behind Spoke FortiGate can reach a server via two possible links:
The options are as follows: A) Routing through a default static route towards FGT-1. B) Routing through the OSPF default route advertised through FGT-2.
The FortiGate administrator's goal in this case would be to load balance the traffic towards both links at the same time thus he/she adjusted the Administrative Distance (AD) of the static route to 110 so it can be equal with the OSPF one:
# config router static edit X set gateway 10.10.10.10 set distance 110 set device "wan1" next end
Issuing the command get router info routing-table all on the Spoke FortiGate will produce an output similar to the following:
Routing table for VRF=0
Note: Only one protocol's route to the same destination will be processed by the kernel at the same time. As a result, FortiOS will choose to route packets through the static default route, and will only use the OSPF default route when the wan1 link becomes inactive. |
