Reference Guide

Data Center Bridging (DCB) | 299
DCBx Prerequisites and Restrictions
The following prerequisites and restrictions apply when you configure DCBx operation on a port:
• DCBx requires LLDP in both send (TX) and receive (RX) mode to be enabled on a port interface
(
protocol lldp mode command; refer to the example in CONFIGURATION versus INTERFACE
Configurations in the Link Layer Discovery Protocol (LLDP) chapter). If multiple DCBx peer ports
are detected on a local DCBx interface, DCBx is shut down on the interface.
• The DCBx version you configure on an interface (see DCBx Configuration Procedure) determines the
server CNA traffic that is handled:
• CEE-DCBX supports T11-compliant Gen-2 CNAs.
• CIN-DCBX supports Gen-1 CNAs.
• IEEE 802.1Qaz (Draft 2.5) supports Gen-2 CNAs.
You can also configure an interface to operate using the DCBx version received from a peer
(auto-configure option). In this case, the S5000 detects the capabilities of a CNA and auto-configures
the interface to the correct DCBx mode.
• The CIN version of DCBx supports only PFC, ETS, and FCOE; it does not support iSCSI, backward
congestion management (BCN), logical link down (LLDF), and network interface virtualization
(NIV).