DCBx (8325 Switch Series only)

DCBx is a discovery and capability exchange protocol to discover peers and negotiate Data Center Bridging configuration. DCBx is specified as part of IEEE 802.1Qaz-2011. DCBx uses LLDP as the underlying protocol for exchange of parameters with the peer. The DCBx parameters are exchanged as LLDP TLVs.

There are two main versions of DCBx: IEEE DCBx and CEE DCBx. ArubaOS-CX switches support the IEEE DCBx version which uses an OUI of 0x0080c2.

DCBx supports VSX synchronization. For more information about enabling VSX synchronization, see the Virtual Switching Extension (VSX) Guide for your switch and software version.

DCBx LLDP TLVs supported by ArubaOS-CX:

• PFC (Priority Flow Control) TLV with subtype 0x0b.

  • Advertises priorities that are configured in the switch as lossy/lossless.

  • PFC TLVs are symmetrical which means they have to match between peers.

  • If a peer PFC priority configuration does not match switch configuration, a misconfiguration error is displayed by the command show dcbx interface.

• ETS (Enhanced Transmission Selection) configuration TLV with subtype 0x09.

  • Advertises the configured bandwidth reservation and the transmission algorithm used for each traffic class.

  • This is an asymmetric TLV which means the configuration does not have to match between peers.

• ETS (Enhanced Transmission Selection) recommendation TLV with subtype 0x0a.

  • If the peer device is willing to accept switch ETS configuration, then the contents of this TLV can be used by peer to configure itself.

  • The switch sends the current ETS configuration as the ETS recommended values.

• Application priority TLV with subtype 0x0c.

  • This is an informational TLV that tells the peer to map certain application traffic to a priority.

  • The user has to correctly configure this information using the application priority command.

  • This allows the peer to map applications to appropriate lossless priority configured on the switch.