H3C Technologies H3C Intelligent Management Center - Manual (Page 37)

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Table 5 shows the DCBX parameters required on FCoE switches and application of these parameters on
the CNAs.
Table 5 DCBX parameters
DCBX parameters on switches Application of these parameters on the CNAs
Enable LLDP.
Enable LLDP both globally and on an interface, and
enable the interface to advertise DCBX TLVs.
The switch distributes APP, ETS, and PFC parameter
values to attached servers and storage devices.
APP parameters.
The switch resets the 802.1p priority of received FCoE
and FIP frames to its expected value. After successful negotiation, the server and storage
device include the 802.1p priority expected by the
switch in outgoing FCoE and FIP frames.
ETS parameters.
The switch maps the 802.1p priority of FCoE and FIP
frames to a local precedence value. Then, it assigns
the two types of frames received on the interface to a
WRR queue based on the local precedence value. The
WRR queue is subject to the configured minimum
guaranteed bandwidth.
After successful negotiation, the server and storage
device send FCoE and FIP frames at a rate no more
than the committed bandwidth of the interface. This
prevents packet loss due to congestion.
PFC parameters.
The switch enables PFC for a specific 802.1p priority
of FCoE and FIP frames on the interface connecting to
a server. The switch can thus notify the server to slow
down transmission when congestion occurs.
After successful negotiation, the server and storage
device enable PFC for the same 802.1p priority.
VFM automatically configure some of the DCBX parameters, so operators need to configure only the
following parameters:
• ACLs for matching FCoE and FIP frames and for resetting the 802.1p priority of these frames, class
name, behavior name, and QoS policy name.
• 802.1p priority expected by the switch.
• Local precedence mapped by the 802.1p priority.
• Guaranteed bandwidth for ETS.
• WRR queuing type.
By default, default DCBX parameters are used on all FCoE switches in VFM and their interfaces.
To configure default DCBX parameters:
1. Click the Service tab.
2. From the navigation tree, select VAN Fabric Manager > SAN Configuration > Default DCBX
Params.
3. Click the Advanced Configuration link to configure the following parameters:
{
802.1p Priority—Enter the 802.1p priority reset for FCoE and FIP frames.
{
Local Precedence—Enter the local precedence to which the 802.1p priority is mapped. A local
precedence value corresponds to a WRR queue number.
{
Guaranteed Bandwidth for ETS—Select a percentage of the interface bandwidth consumed by
FCoE and FIP frames. The greater the percentage value, the greater scheduling weight the
WRR queue has.