Example 2: Routing table update
The following example illustrates the flow of a packet when there is a routing table update. As this is low level, there is no security involved. This example includes the following steps:
1. FortiGate unit receives routing update packet
2. Packet intercepted by FortiGate unit interface
2.1 Link level CRC and packet size checking. If the size is correct, the packet continues, otherwise it is dropped.
3. DoS sensor - checks are done to ensure the sender is valid and not attempting a denial of service attack.
4. IP integrity header checking, verifying the IP header length, version and checksums.
5. Stateful policy engine
5.1 Management traffic (local traffic)
6. Routing module
6.1 Update routing table
Figure 321 illustrates the process steps.
