EasyManua.ls Logo

Dell S4048T - Page 307

Dell S4048T
1277 pages
To Next Page IconTo Next Page
To Next Page IconTo Next Page
To Previous Page IconTo Previous Page
To Previous Page IconTo Previous Page
Loading...
During the congestion, [traffic pump on priorities 3 and 4 from PORT A and PORT C is at full line rate], PORT
A and C send out the PFCs to rate the traffic limit. Egress drops are not observed on Port B since traffic flow
on priorities is mapped to loss less queues.
Port B acting as Ingress
If the traffic congestion is on PORT B , Egress DROP is on PORT A or C, as the PFC is not enabled on PORT B.
Refer the following configuration for queue to dot1p mapping:
Dell(conf)#do show qos dot1p-queue-mapping
Dot1p Priority : 0 1 2 3 4 5 6 7 -> On ingress interfaces[Port A and C]
we used the PFC on priority level.
Queue : 0 0 0 1 2 3 3 3 -> On Egress interface[Port B] we used
no-drop queues.
Lossless traffic egresses out the no-drop queues. Ingress 802.1p traffic from PFC-enabled peers is
automatically mapped to the no-drop egress queues.
When configuring lossless queues on a port interface, consider the following points:
By default, no lossless queues are configured on a port.
A limit of two lossless queues is supported on a port. If the number of lossless queues configured
exceeds the maximum supported limit per port (two), an error message is displayed. Reconfigure the
value to a smaller number of queues.
If you configure lossless queues on an interface that already has a DCB map with PFC enabled (pfc on),
an error message is displayed.
Table 19. Configuring Lossless Queues on a Port Interface
Step Task Command Command Mode
1 Enter INTERFACE Configuration mode.
interface
{tengigabitEthernet
slot/port [/
subport] |
fortygigabitEthernet
slot/port}
CONFIGURATION
2
Open a DCB map and enter DCB map
configuration mode.
dcb-map name
INTERFACE
3
Disable PFC.
no pfc mode on
DCB MAP
4
Return to interface configuration mode.
exit
DCB MAP
5
Apply the DCB map, created to disable the PFC
operation, on the interface
dcb-map {name |
default}
INTERFACE
6
Configure the port queues that still function as
no-drop queues for lossless traffic. For the
dot1p-queue assignments.
pfc no-drop
queuesqueue-range
INTERFACE
Data Center Bridging (DCB) 307

Table of Contents

Related product manuals