Configuring GMB for outbound traffic
For any port, group of ports, or static trunk, you can configure either the default minimum bandwidth settings for
each outbound priority queue or a customized bandwidth allocation. For most applications, Hewlett Packard
Enterprise recommends configuring GMB with the same values on all ports on the switch so that the outbound
traffic profile is consistent for all outbound traffic. However, there may be instances where it may be advantageous
to configure special profiles on connections to servers or to the network infrastructure (such as links to routers,
other switches, or to the network core).
Syntax:
[no] int
<port-list|trk_#>
bandwidth-min output
Configures the default minimum bandwidth allocation for the outbound priority queue for each port or static trunk
in the
<port-list|trk_#>
. In the eight-queue configuration, the default values per priority queue are:
• Queue 1 (low priority): 2%
• Queue 2 (low priority): 3%
• Queue 3 (normal priority): 30%
• Queue 4 (normal priority): 10%
• Queue 5 (medium priority): 10%
• Queue 6 (medium priority): 10%
• Queue 7 (high priority): 15%
• Queue 8 (high priority): 20%
The
no
form of the command disables GMB for all ports and trunks in the
<port-list>
. In this state, which is
the equivalent of setting all outbound queues on a port or static trunk to
0
(zero), a high level of higher-priority
traffic can starve lower-priority queues, which can slow or halt lower-priority traffic in the network.
You can configure bandwidth minimums from either the global configuration level (as shown above) or from the
port or static trunk context level. For information on outbound port queues, see
Syntax:
[no] int <
<port-list|trk_#>
> bandwidth-min output [0-100|strict] [0-100]
Select a minimum bandwidth.
For ports and trunks in
<port-list|trk_#>
, specifies the minimum outbound bandwidth as a percent of the
total bandwidth for each outbound queue. The queues receive service in descending order of priority of each port.
NOTE:
For application to static trunk interfaces (2920 and 5400R only), GMB enforcement is applied
individually to each port belonging to the trunk, and not to the trunk as a whole.
You must specify a bandwidth percent value for all except the highest priority queue, which may instead be set to
"strict" mode. The sum of the bandwidth percentages below the top queue cannot exceed 100%. (
0
is a value for
a queue percentage setting.)
Configuring a total of less than 100% across the eight queues results in unallocated bandwidth that remains
harmlessly unused unless a given queue becomes oversubscribed. In this case, the unallocated bandwidth is
apportioned to oversubscribed queues in descending order of priority. For example, if you configure a minimum of
10% for queues 1 to 7 and 0% for queue 8, the unallocated bandwidth is available to all eight queues in the
following prioritized order:
Chapter 6 Port Traffic Controls
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