Intra-Subnet QoS
MAC-Based
Traffic Groupings
Verifying IPQoS settings. To verify settings made for IPQoS traffic
groupings, use the command:
show ipqos
™
Intra-Subnet QoS
(ISQ) allows the application of any IPQoS
commands to be effective within a subnet (VLAN) instead of only
applying the QoS when traversing a routed subnet. The command
syntax for all IPQoS commands remains the same; ISQ is simply
enabled on a per VLAN basis.
Because ISQ instructs the switch to look at IP addresses within a
VLAN, the normal MAC-based learning and refreshing for layer 2
switching is altered for traffic that matches an IPQoS traffic grouping.
Instead, learning and refreshing is done based on IP information in
the packets. As a result, it is necessary to increase the FDB aging
timer comfortably above a normal ARP table refresh time to 50
minutes (3,000 seconds). This occurs automatically when ISQ is
enabled. ISQ should not be used on VLANs with clients that have
statically defined ARP tables. To verify the FDB timer, use the
following command:
show fdb
The aging time is displayed at the end of the table.
QoS profiles can be assigned to destination MAC addresses. The
various options that fall into this category are as follows:
Permanent
Dynamic
Blackhole
Broadcast/unknown rate limiting
MAC-based traffic groupings are configured using the following
command:
create fdbentry <mac_address> vlan <name>
[blackhole | port <portlist> | dynamic]
qosprofile <qosname>
AT-9108, AT-8518, AT-8525, and AT-8550 User's Guide
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