Technical Tip: How to view the multicast and broadcast traffic hitting on the FortiAP

In certain cases, the FortiAP's CPU utilization is higher than normal, which results in delay and impairs network performance overall.

When the FortiAP is hitting a huge amount of traffic, there are cases when the CPU and memory on the FortiAP spike up.

For example, refer to the below commands on the FortiAP CLI:

perf

CPU Load : 100%
CPU1 Load : 43%
CPU2 Load : 43%
CPU3 Load : 31%
CPU4 Load : 42%

Memory Usage: 99% 

To see if memory is used by daemon or kernel:

meminfo
MemTotal: 890108 kB
MemFree: 267268 kB
MemAvailable: 345988 kB
Buffers: 15688 kB
Cached: 64036 kB
SwapCached: 0 kB
Active: 79588 kB
Inactive: 26504 kB
Active(anon): 27884 kB
Inactive(anon): 480 kB
Active(file): 51704 kB
Inactive(file): 26024 kB
Unevictable: 0 kB
Mlocked: 0 kB
SwapTotal: 0 kB
SwapFree: 0 kB
Dirty: 0 kB
Writeback: 0 kB
AnonPages: 26368 kB
Mapped: 16868 kB
Shmem: 1996 kB
Slab: 444152 kB
SReclaimable: 15128 kB
SUnreclaim: 429024 kB
KernelStack: 3120 kB
PageTables: 876 kB
NFS_Unstable: 0 kB
Bounce: 0 kB
WritebackTmp: 0 kB
CommitLimit: 445052 kB
Committed_AS: 52776 kB
VmallocTotal: 258998208 kB
VmallocUsed: 0 kB
VmallocChunk: 0 kB

Log in to the FortiAP CLI: 

tcpdump -i eth0 ether broadcast or ether multicast