Netgear M4300-24X24F (XSM4348S) - Stackable Managed Switch with 48x10G including 24x10GBASE-T and 24xSFP+ Layer 3 Guia Do Programa
Data Center Commands
980
M4200 and M4300 Series ProSAFE Managed Switches
Priority-Based Flow Control Commands
If flow control is enabled on a physical link, it applies to all traffic on the link. If congestion
occurs, the hardware sends pause frames that temporarily suspend the traffic flow. Pausing
traffic helps to prevent buffer overflow and dropped frames.
occurs, the hardware sends pause frames that temporarily suspend the traffic flow. Pausing
traffic helps to prevent buffer overflow and dropped frames.
Priority-based flow control (PFC) provides a way to distinguish which traffic on physical link is
paused when congestion occurs, based on the priority of the traffic. You can configure an
interface to pause high priority traffic only (that is, loss-sensitive traffic) when necessary to
prevent dropped frames, while allowing traffic with greater loss tolerance to continue to flow
on the interface.
paused when congestion occurs, based on the priority of the traffic. You can configure an
interface to pause high priority traffic only (that is, loss-sensitive traffic) when necessary to
prevent dropped frames, while allowing traffic with greater loss tolerance to continue to flow
on the interface.
Priorities are differentiated by the priority field in the IEEE 802.1Q VLAN header, which
identifies an IEEE 802.1p priority value. These priority values must be mapped to internal
class-of-service (CoS) values on the switch.
identifies an IEEE 802.1p priority value. These priority values must be mapped to internal
class-of-service (CoS) values on the switch.
To enable priority-based flow control for a particular CoS value on an interface, do the
following:
following:
1.
Ensure that VLAN tagging is enabled on the interface so that the 802.1p priority values
are carried through the network (see
are carried through the network (see
2.
Ensure that 802.1p priority values are mapped to CoS values on the switch (see
If priority flow control is disabled, the interface defaults to the IEEE 802.3x flow control setting
for the interface. If priority based flow control is enabled, the interface does not pause CoS
unless at least one no-drop priority is configured.
for the interface. If priority based flow control is enabled, the interface does not pause CoS
unless at least one no-drop priority is configured.
priority-flow-control mode
Use the priority-flow-control mode on command in Datacenter-Bridging Config
mode to enable Priority-Flow-Control (PFC) on the given interface.
mode to enable Priority-Flow-Control (PFC) on the given interface.
PFC must be enabled before FIP snooping can operate over the interface. VLAN tagging
(trunk or general mode) must be enabled on the interface to carry the dot1p value through the
network. Additionally, mapping between dot1p and the queues must be set to one-to-one.
(trunk or general mode) must be enabled on the interface to carry the dot1p value through the
network. Additionally, mapping between dot1p and the queues must be set to one-to-one.
If PFC is enabled on an interface, the normal pause control mechanism is operationally
disabled.
disabled.
Default
off
Format
priority-flow-control mode {on | off}
Mode
Datacenter-Bridging Config mode