This section describes commands to display information related to PFC after LLDP and DCB are configured and provides examples to show the use of these commands.
The following command displays the priority definitions and the effective PFC mappings on the datalink:
$ dladm show-linkprop -p pfcmap,pfcmap-remote datalink
On a datalink with matching PFC information between the local and remote peers, the values of the EFFECTIVE column for pfcmap and pfcmap-remote properties are identical regardless of the value set for the pfcmap property. If the ability to synchronize is disabled on the local host, then the EFFECTIVE field for the pfcmap property reflects the value of the pfcmap property for the local host.Example 41 Displaying PFC-Related Datalink Properties
This example shows how to display the status of physical datalink properties that are related to priority-based flow control.
$ dladm show-linkprop -p pfcmap,pfcmap-remote net0 LINK PROPERTY PERM VALUE EFFECTIVE DEFAULT POSSIBLE net0 pfcmap rw 11111111 11111111 11111111 00000000-11111111 net0 pfcmap-remote r- -- -- -- --
In the example, the value field for the pfcmap property has the value of 11111111. This value indicates that the PFC mapping on the local host has the default value where all eight priorities are enabled. The EFFECTIVE values for the pfcmap and pfcmap-remote properties are 11111111 and --. These mismatched values for the EFFECTIVE field indicate that the local host has not synchronized its PFC information with the remote peer.
You can use the lldpadm show-agenttlvprop command to verify the value of the willing property and the lldpadm show-agent -r command to check the PFC TLV information from the peer.
The following command displays the PFC TLV property that controls a host's capability to synchronize its PFC mapping with a peer.
$ lldpadm show-agenttlvprop -a agent pfc
where agent is identified by the datalink on which LLDP is enabled.Example 42 Displaying the Capability of the Local Host to Synchronize PFC Information
This example shows how to display the current status of the host's ability to adjust to PFC configurations of the peer.
$ lldpadm show-agenttlvprop -a net0 pfc -p willing AGENT TLVNAME PROPERTY PERM VALUE EFFECTIVE DEFAULT POSSIBLE net0 pfc willing rw off -- on on,off
For more information, see Setting the PFC TLV Units.
The PFC Pending value returns a True status if PFC information between the host and the peer does not converge. After the mismatch is resolved, the status of PFC Pending returns to False.
The following command alerts you to a mismatch of PFC mapping information between the local host and the peer.
$ lldpadm show-agent -lv -o "PFC Pending" agent
$ lldpadm show-agent -lv -o "PFC Pending" agentExample 43 Verifying Symmetry of PFC Information Between Host and Peer
The following example shows how to verify in actual running time whether PFC information is synchronized between the host and peer, or whether a mismatch occurs.
$ lldpadm show-agent -lv -o "PFC Pending" net0 PFC Pending: True
To display all the information that the agent advertises, use the –v (verbose) option of the lldpadm show-agent command:
$ lldpadm show-agent -v net0
The following command displays PFC information about the physical link with regards to enabled priorities on the NIC:
$ dladm show-phys -D pfc datalinkExample 44 Displaying CoS Priority Definitions
This example shows how to display the current priority definitions on a specific physical link based on the value of the pfcmap property. For example, assume that pfcmap is configured as 01000000. To display the corresponding priority mappings on the physical link, you would proceed as follows:
$ dladm show-phys -D pfc net0 LINK COS PFC PFC_EFFECT CLIENTS net0 0 YES NO net0,vnic1 1 YES YES vnic2 2 YES NO vnic3 3 YES NO vnic4 4 YES NO vnic5 5 YES NO vnic6 6 YES NO vnic7 7 YES NO vnic8
For the physical link net0, priority is enabled for all VNIC clients configured over the datalink. However, the local host adjusts its PFC mapping to the PFC mapping on the peer, as shown by the values of the PFC_EFFECT field, where priority is disabled on COS 0 and 2-7. As a result, no PFC frames would be exchanged for traffic on any VNIC except vnic2 regardless of the availability of resources. With this configuration, packet drops are allowed on traffic that flows on all VNICs except vnic2. For traffic on vnic2, PFC PAUSE frames are sent when traffic congestion occurs to prevent packet loss on this client.