User Manual

Rev 4.70
Mellanox Technologies
51
Step 5. Enable PFC on ports that face the network.
8.7.4.1 Using Global Pause Flow Control (GFC)
 To enable GFC on ports that face the hosts, perform the following:
8.7.4.2 Using Priority Flow Control (PFC)
 To enable PFC on ports that face the hosts, perform the following:
8.7.5 Configuring Router (PFC only)
The router uses L3's DSCP value to mark the egress traffic of L2 PCP. The required mapping,
maps the three most significant bits of the DSCP into the PCP. This is the default behavior, and
no additional configuration is required.
8.7.5.1 Copying Port Control Protocol (PCP) between Subnets
The captured PCP option from the Ethernet header of the incoming packet can be used to set the
PCP bits on the outgoing Ethernet header.
8.7.6 Configuring the RoCE Mode
Configuring the RoCE mode requires the following:
• RoCE mode is configured per-driver and is enforced on all the devices in the system
RoCE mode can be enabled and disabled via PowerShell.
•
(config-if-Et10)# speed forced 40gfull
(config-if-Et10)# channel-group 11 mode active
(config)# interface et20
(config-if-Et20)# load-interval 5
(config-if-Et20)# speed forced 40gfull
(config-if-Et20)# switchport trunk native vlan tag
(config-if-Et20)# switchport trunk allowed vlan 11
(config-if-Et20)# switchport mode trunk
(config-if-Et20)# dcbx mode ieee
(config-if-Et20)# priority-flow-control mode on
(config-if-Et20)# priority-flow-control priority 3 no-drop
(config)# interface et10
(config-if-Et10)# flowcontrol receive on
(config-if-Et10)# flowcontrol send on
(config)# interface et10
(config-if-Et10)# dcbx mode ieee
(config-if-Et10)# priority-flow-control mode on
(config-if-Et10)# priority-flow-control priority 3 no-drop
The supported RoCE modes depend on the firmware installed. If the firmware does not
support the needed mode, the fallback mode would be the maximum supported RoCE
mode of the installed NIC.