3.1.4 Notes on using flow detection

<Structure of this section>

(1) QoS flow-detection for frames with VLAN Tag

Either of the following conditions must be satisfied to perform QoS flow detection on the receiving side by an Ethernet type for a MAC condition, an IPv4 condition, or an IPv6 condition specified as the flow detection condition for a frame that has two VLAN tags:

The VLAN tunneling functionality is not active on the Switch.
The VLAN tunneling functionality is active on the Switch but frames were received by a trunk port.

(2) QoS flow-detection for IPv4 fragmented packets

If you perform QoS flow detection by using a TCP/UDP header or ICMP header specified as a flow detection condition for a fragmented IPv4 packet, the second and subsequent fragments cannot be detected because the TCP/UDP header and ICMP header are not in those packets. To perform QoS flow detection for frames that include fragmented packets, specify the MAC header or IP header in the flow detection conditions.

(3) QoS flow-detection for IPv6 packets with extension headers

For IPv6 packets whose IPv6 extension header is not a single-stage Hop-by-Hop Options, a QoS flow detection using TCP/UDP header or ICMP header as the flow detection condition cannot be performed.

To perform QoS flow detection for the corresponding packet, specify MAC headers and IPv6 headers as the flow detection conditions.

(4) Operation When Applying QoS Entries

On the Switch, a QoS entry may be applied to an interface*, or other QoS entries may be detected until the specified QoS entry is applied. In this case, statistics for the QoS entries that detected packets are collected.

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When a QoS list containing one or more entries is applied to the interface by using the QoS flow group command
When a QoS flow list is applied by using the QoS flow group command to add an entry
When a QoS entry is applied when the switch is started, the copy operation command is executed, or the restart vlan operation command is executed

(5) Operation when changing QoS entries

If a QoS entry applied to an interface is changed on the Switches, detectable frames cannot be detected until the change has been applied. Consequently, such frames are detected as if they matched another QoS entry.

(6) Simultaneous operation with other functions

Frames are discarded in the following cases. However, if QoS entries for which bandwidth monitoring is not used for the receiving interface are set and matched, the statistical information of the matching QoS entries is collected.

Frames are received from the VLAN port whose data transfer status is Blocking (data transfer stopped).
Frames are received from a port specified by the inter-port relay blocking functionality.
Frames without a VLAN tag are received when the native LAN is not set as the VLAN that uses a trunk port for sending and receiving frames.
Received frames that have a VLAN tag are not set for a VLAN that uses a trunk port for sending and receiving frames.
Frames with a VLAN Tag are received at access, protocol or MAC ports.
Frames that match a filter entry specifying discard (including an implicit discard entry) are received.
Frames are discarded by the MAC address learning functionality.
Frames are discarded by IGMP snooping or MLD snooping.
Frames are discarded by storm control.
When a packet is discarded by IP layer process