Disabling DCBX to Disable PFC Autonegotiation on EX Series Switches (CLI Procedure)
As part of its autonegotiation capabilities, the Data Center Bridging Capability Exchange protocol (DCBX) automatically does the following:
Advertises the priority flow control (PFC) configuration of the local interfaces to directly connected peers (switches and data center devices such as servers)
Detects the PFC capabilities of the connected peers
Enables the local interface’s PFC capabilities if DCBX detects that the peer interface’s PFC configuration is the same as the PFC configuration of the local interface.
Disables the local interface’s PFC capabilities if DCBX detects that the peer interface’s PFC configuration is not the same as the PFC configuration of the local interface.
DCBX is enabled by default on all 10-Gigabit Ethernet interfaces on EX4500 switches. You can manually override DCBX control of the PFC operational state on a per-interface basis. You might want to disable autonegotiation if the DCB peer does not support PFC.
To disable the DCBX control of the PFC operational state:
On an individual interface:
[edit protocols] user@switch# set dcbx interface interface-name priority-flow-control no-auto-negotiation
On all 10-Gigabit Ethernet interfaces:
[edit protocols] user@switch# set dcbx interface all priority-flow-control no-auto-negotiation