Table of Contents
Advertisement
Auto-Detection and Manual Configuration of
the DCBx Version
When operating in Auto-Detection mode (the DCBx version auto command), a DCBx port automatically
detects the DCBx version on a peer port. Legacy CIN and CEE versions are supported in addition to the
standard IEEE version 2.5 DCBx.
A DCBx port detects a peer version after receiving a valid frame for that version. The local DCBx port
reconfigures to operate with the peer version and maintains the peer version on the link until one of the
following conditions occurs:
•
The switch reboots.
•
The link is reset (goes down and up).
•
User-configured CLI commands require the version negotiation to restart.
•
The peer times out.
•
Multiple peers are detected on the link.
If you configure a DCBx port to operate with a specific version (the DCBx version {cee | cin | ieee-
v2.5} command in the
version, including fast and slow transmit timers and message formats. If a DCBx frame with a different version
is received, a syslog message is generated and the peer version is recorded in the peer status table. If the
frame cannot be processed, it is discarded and the discard counter is incremented.
NOTE:
Because DCBx TLV processing is best effort, it is possible that CIN frames may be processed when
DCBx is configured to operate in CEE mode and vice versa. In this case, the unrecognized TLVs cause the
unrecognized TLV counter to increment, but the frame is processed and is not discarded.
Legacy DCBx (CIN and CEE) supports the DCBx control state machine that is defined to maintain the
sequence number and acknowledge the number sent in the DCBx control TLVs.
Behavior of Tagged Packets
The below is example for enabling PFC for priority 2 for tagged packets. Priority (Packet Dot1p) 2 will be
mapped to PG6 on PRIO2PG setting. All other Priorities for which PFC is not enabled are mapped to default
PG – PG7.
Classification rules on ingress (Ingress FP CAM region) matches incoming packet-dot1p and assigns an
internal priority (to select queue as per Table 1 and Table 2).
The internal Priority assigned for the packet by Ingress FP is used by the memory management unit (MMU) to
assign the packet to right queue by indexing the internal-priority to queue map table (TABLE 1) in hardware.
PRIO2COS setting for honoring the PFC protocol packets from the Peer switches is as per above Packet-
Dot1p->queue table (Table 2).
The packets that come in with packet-dot1p 2 alone will be assigned to PG6 on ingress.
Configuring
DCBx), DCBx operations are performed according to the configured
Data Center Bridging (DCB)
314
Advertisement
Table of Contents
Troubleshooting
