Advanced Traffic Management Guide K/KA/KB.15.15

For
information
on
globally-co nfigured
ICMP,
see
the
Multicast
and
Routing
Guide
for
your
switch.
priority priority-value Configures the 802.1p class of service (CoS)
bits in Layer 2 frames of matching packets
in a specified traffic class. Valid CoS values
range from 0 to 7.
The 802.1p CoS value controls the outbound
port-queue priority for traffic leaving the
switch. In an 802.1Q VLAN network,
downstream devices may honor or change
the 802.1p priority in incoming packets.
Table 17 (page 242) shows how the Layer 2
802.1p priority value determines to which
outbound port queue a packet is sent both
on the switch and on a downstream device.
The 802.1p CoS numeric value (from 0 to
7) corresponds to the hexadecimal
equivalent of the three binary 0 and 1 bit
settings in the Layer 2 header. For example
if the CoS bit values are 1 1 1, the numeric
value is 7 (1+2+4). Similarly, if the CoS bits
are 0 1 1, the numeric value is 3 (1+2+0).
NOTE: If you want the 802.1p CoS priority
settings included in outbound packets to be
honored on downstream devices, configure
tagged VLANs on the appropriate inbound
and outbound ports.
ip-precedence
precedence-value
Configures the IP precedence value in the
IPv4 ToS byte or IPv6 Traffic Class byte of
matching packets in a specified traffic class.
Valid IP precedence values are either a
numeric value from 0 (low priority) to 7 (high
priority) or its corresponding name:
0 routine
1 priority
2 immediate
3 flash
Configuring QoS actions in a policy 227