Users Guide

On the S4820T, PFC and ETS use DCBx to exchange link-level conguration with DCBx peer devices.
Figure 35. DCBx Sample Topology
DCBx Prerequisites and Restrictions
The following prerequisites and restrictions apply when you congure 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 Congurations 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).
Conguring DCBx
To congure DCBx, follow these steps.
For DCBx, to advertise DCBx TLVs to peers, enable LLDP. For more information, refer to Link Layer Discovery Protocol (LLDP).
Congure DCBx operation at the interface level on a switch or globally on the switch. To congure the S4820Tsystem for DCBx
operation in a data center network, you must:
1. Congure ToR- and FCF-facing interfaces as auto-upstream ports.
2. Congure server-facing interfaces as auto-downstream ports.
3. Congure a port to operate in a conguration-source role.
4. Congure ports to operate in a manual role.
1. Enter INTERFACE Conguration mode.
CONFIGURATION mode
interface type slot/port
2. Enter LLDP Conguration mode to enable DCBx operation.
INTERFACE mode
[no] protocol lldp
3. Congure the DCBx version used on the interface, where: auto congures the port to operate using the DCBx version
received from a peer.
PROTOCOL LLDP mode
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Data Center Bridging (DCB)