FortiGate Next Generation Firewall utilizes purpose-built security processors and threat intelligence security services from FortiGuard labs to deliver top-rated protection and high performance, including encrypted traffic.
This article describes how to clear the FortiGate route cache. For some reason, it may be required to clear the route cache on FortiGate.
Scope
FortiGate under Linux kernel 3.6.
Solution
Route cache is a Linux kernel component that is consulted before the actual route lookup.
If the lookup into this cache does not produce a match, the packet is forwarded based on a FIB lookup. The cache is a hash table and a lookup into this table is performed based on a key constructed from the tuples seen in the IP packet header such as its source IP, destination IP, and related information.
To clear the route cache, from CLI issue the below command:
diag ip rtcache flush
FortiGates that are running on Linux kernel 3.6 or above will not have a Router cache anymore. This command will not be available.
