C
ONFIGURING
THE
S
WITCH
2-86
CLI – The following example globally enables IP Precedence service on
the switch, maps IP Precedence value 1 to CoS value 0 on port 5, and then
displays all the IP Precedence settings for that port. (Note that the setting
is global and applies to all ports on the switch.)
Mapping DSCP Priority
The DSCP is six bits wide, allowing coding for up to 64 different
forwarding behaviors. The DSCP replaces the ToS bits, and it retains
backward compatibility with the three precedence bits so that non-DSCP
compliant, ToS-enabled devices, will not conflict with the DSCP mapping.
Based on network policies, different kinds of traffic can be marked for
different kinds of forwarding. The DSCP default values are defined in the
following table. Note that all the DSCP values that are not specified are
mapped to CoS value 0.
Console(config)#map ip precedence 3-156
Console(config)#interface ethernet 1/5 3-85
Console(config-if)#map ip precedence 1 cos 0 3-157
Console(config-if)#end
Console#show map ip precedence ethernet 1/5 3-160
Precedence mapping status: disabled
Port Precedence COS
--------- ---------- ---
Eth 1/ 5 0 0
Eth 1/ 5 1 0
Eth 1/ 5 2 2
Eth 1/ 5 3 3
Eth 1/ 5 4 4
Eth 1/ 5 5 5
Eth 1/ 5 6 6
Eth 1/ 5 7 7
Console#
IP DSCP Value CoS Value
00
81
10, 12, 14, 16 2
18, 20, 22, 24 3
26, 28, 30, 32, 34, 36 4