Owners Manual

Figure 33. DCBx Sample Topology
DCBx Prerequisites and Restrictions
The following prerequisites and restrictions apply when you configure DCBx operation on a port:
• For DCBx, on a port interface, enable LLDP in both Send (TX) and Receive (RX) mode (the 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, LLDP is shut down.
• 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).
Configuring DCBx
To configure DCBx, follow these steps.
For DCBx, to advertise DCBx TLVs to peers, enable LLDP. For more information, refer to Link Layer
Discovery Protocol (LLDP).
Configure DCBx operation at the interface level on a switch or globally on the switch. To configure the
S4820T system for DCBx operation in a data center network, you must:
1. Configure ToR- and FCF-facing interfaces as auto-upstream ports.
2. Configure server-facing interfaces as auto-downstream ports.
3. Configure a port to operate in a configuration-source role.
4. Configure ports to operate in a manual role.
1. Enter INTERFACE Configuration mode.
CONFIGURATION mode
interface type slot/port
2. Enter LLDP Configuration mode to enable DCBx operation.
INTERFACE mode
Data Center Bridging (DCB)
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