Hello
@asit1111990 wrote:
Hello Friends,
l not cleat what is a dscp mutation map and how to be read its matrix .
It would be great if someone could explain it
When you enable Qos on a switch - DCSP re-write is also enabled
as such any dscp marked traffic coming into the switch it will be over wrote to the default DSCP re-write value 0
Switch#sh mls qos
QoS is disabled
QoS ip packet dscp rewrite is enabled < Only applicable when QOS is enabled)
Switch(config)#mls qos
Switch#sh mls qos
QoS is enabled
QoS ip packet dscp rewrite is enabled
So to negate this you can create a DSCP mutation class to change this behavior:
DSCP mutation example:
sh mls qos maps dscp-mutation
Dscp-dscp mutation map:
Default DSCP Mutation Map:
d1 : d2 0 1 2 3 4 5 6 7 8 9
---------------------------------------
0 : 00 01 02 03 04 05 06 07 08 09
1 : 10 11 12 13 14 15 16 17 18 19
2 : 20 21 22 23 24 25 26 27 28 29
3 : 30 31 32 33 34 35 36 37 38 39
4 : 40 41 42 43 44 45 46 47 48 49
5 : 50 51 52 53 54 55 56 57 58 59
6 : 60 61 62 63
conf t
mls qos map dscp-mutation STAN 1 to 50
int x/x
mls qos dscp-mutation STAN
mls qos trust dscp
sh mls qos maps dscp-mutation STAN
DSCP Mutation Map: STAN
sh mls qos maps dscp-mutation STAN
Dscp-dscp mutation map:
STAN:
d1 : d2 0 1 2 3 4 5 6 7 8 9
---------------------------------------
0 : 00 50 02 03 04 05 06 07 08 09
1 : 10 11 12 13 14 15 16 17 18 19
2 : 20 21 22 23 24 25 26 27 28 29
3 : 30 31 32 33 34 35 36 37 38 39
4 : 40 41 42 43 44 45 46 47 48 49
5 : 50 51 52 53 54 55 56 57 58 59
6 : 60 61 62 63
sh mls qos int x/x | in DSCP|dscp
trust state: trust dscp
trust mode: trust dscp
DSCP Mutation Map: STAN
So now any marked DSCP value of 1 incoming into this interface when QOS is enabled will be re-wrote to DSCP 50
res
Paul
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Kind Regards
Paul
