My storage engineers are seeing latency they are attributing to the network 20-30ms to from Dell/VMWare ESX servers - as seen in the Dell management utility. Dell blames the network and says the problem is that Flow Control is not enabled.
When I went to try and enable flow control I was disappointed to find:
sw-3172-a(config-if)# flowcontrol receive on
ERROR: This CLI is not supported on n3k platform
and later saw:
"link-level flowcontrol (LLFC) is not supported on the Nexus 3000 and 3100 series. It is supported on the Nexus 3500 series and Nexus 9000"
https://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus3000/sw/release/70322c/n3k_70322c_nxos_rn.html
Is that the end of the story? I see there is another type of flow control "priority flow control". Would that likely serve the the same purpose for Dell Compellent needs? Looks like a lot of configuration. What I am seeing is the Compellent SAN sending RxPause frames to the 3172. Any insight on this pairing is appreciated!
# sho int flowcontrol
--------------------------------------------------------------------------------
Port Send FlowControl Receive FlowControl RxPause TxPause
admin oper admin oper
--------------------------------------------------------------------------------
Eth1/1 off off off off 622377865 0
Eth1/2 off off off off 632037851 0
Eth1/3 off off off off 374231740 0
Eth1/4 off off off off 377617928 0
Eth1/5 off off off off 888908 0
Eth1/6 off off off off 16576 0
https://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus3000/sw/qos/602_U1_1/b_3k_QoS_Config_602_U11/b_3k_QoS_Config_602_U11_chapter_0101.html
