Technical Tip : Traffic statistics on VLAN interfaces over a NP4 port are not supported

[gfranceschi]

Description

Please note, that in all FortiOS firmware versions, which are within the scope of this KB article (see the section Scope below); RX and TX counters for VLAN interfaces over a NP4 port do not report correct values.

FortiOS firmware provides incorrect values for the following features, which are all based on these specific counters:
- interface debug commands,
- VLAN interfaces based on aggregate interfaces over NP4 ports,
- interface SNMP monitoring,
- and  'Traffic history' widget.

The root cause of this behaviour is, that NP4 hardware doesn't support traffic statistics of VLAN interfaces due to a hardware limitation and performance impact.

Technically, the VLAN interface counter feature, based on an NP4 hardware, requires a different software implementation for each FortiGate model. Therefore, since any such software implementation is hardware-dependent, a requirement for availability of those statistics on currently unsupported platforms would be considered a new feature request.

To request a future developement of such features on a specific hardware platform, please contact your Fortinet Sales representative.

Remarks:
- The TX and RX counters of a physical NP4 port are displayed correctly.
- The TX and RX counters of an aggregate interface over NP4 ports are also displayed correctly.
   These counters are correct in FortiOS version 4.00 MR3 latest patch, but they are displayed incorrectly in FortiOS version 4.00 MR2.

Reference

Scope

FortiOS version 4.00 MR2 (Patch 15 and below)

FortiOS version 4.00 MR3 (Patch 14 and below)

FortiOS version 5.0.3 (Patch 3 and below)

Workaround
Not available.