Policy dscp/cos 0 asr 9006

[Giuseppe Tomasicchio]

I have to apply a policy to force the cos to 0 for the asr 9006 under the vlan

tried but does not seem to match anything
https://www.cisco.com/c/en/us/td/docs/routers/asr9000/software/asr9k-r6-4/qos/configuration/guide/b-qos-cg-asr9000-64x/b-qos-cg-asr9000-64x_chapter_0110.html#ID691

in theory this should be enough that I added:
policy-map COS0
class class-default
set cos 0
set cos inner 0
!
end-policy-map

e l'ho applicata in out alle due interfacce

RP/0/RSP0/CPU0:ios#sh policy-map interface TenGigE0/1/0/13.720651001
Mon Mar 16 10:51:32.706 CET
TenGigE0/1/0/13.720651001 direction input: Service Policy not installed

I am also looking for if it was possible to disable the functionality for which the 9006 seeing the DSCP = 6 automatically sets COS = 6

Because traffic coming into your network can have the precedence set by outside devices, we recommend that you reset the precedence for all traffic entering your network. By controlling IP precedence settings, you prohibit users that have already set the IP precedence from acquiring better service for their traffic simply by setting a high precedence for all of their packets.

The class-based unconditional packet marking, LLQ, and WRED features can use the IP precedence bits.

[Francesco Molino · Accepted solution]

Hi

I've done a quick lab to show you that PMAP is working.

My host has ip 192.168.10.100.

On my XR:

RP/0/RP0/CPU0:ios#sh ip int brie | ex unas
Tue Mar 17 16:19:19.559 UTC

Interface IP-Address Status Protocol Vrf-Name
GigabitEthernet0/0/0/0 172.31.255.1 Up Up default
GigabitEthernet0/0/0/1 192.168.50.1 Up Up default

RP/0/RP0/CPU0:ios#sh route
Tue Mar 17 16:19:43.142 UTC

Codes: C - connected, S - static, R - RIP, B - BGP, (>) - Diversion path
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
i - ISIS, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, su - IS-IS summary null, * - candidate default
U - per-user static route, o - ODR, L - local, G - DAGR, l - LISP
A - access/subscriber, a - Application route
M - mobile route, r - RPL, t - Traffic Engineering, (!) - FRR Backup path

Gateway of last resort is 172.31.255.2 to network 0.0.0.0

S* 0.0.0.0/0 [1/0] via 172.31.255.2, 00:20:56
C 172.31.255.0/24 is directly connected, 00:20:57, GigabitEthernet0/0/0/0
L 172.31.255.1/32 is directly connected, 00:20:57, GigabitEthernet0/0/0/0
C 192.168.50.0/24 is directly connected, 00:22:55, GigabitEthernet0/0/0/1
L 192.168.50.1/32 is directly connected, 00:22:55, GigabitEthernet0/0/0/1

Ping I ran from client interface on my XR (g0/0/0/1), I force a TOS value 196 (CS6):

RP/0/RP0/CPU0:ios#ping
Tue Mar 17 16:17:40.422 UTC
Protocol [ipv4]:
Target IP address: 192.168.10.100
Repeat count [5]: 20
Datagram size [100]:
Timeout in seconds [2]:
Interval in milliseconds [10]:
Extended commands? [no]: yes
Source address or interface: GigabitEthernet0/0/0/1
Type of service [0]: 196
Set DF bit in IP header? [no]:
Validate reply data? [no]:
Data pattern [0xABCD]:
Loose, Strict, Record, Timestamp, Verbose[none]:
Sweep range of sizes? [no]:
Type escape sequence to abort.
Sending 20, 100-byte ICMP Echos to 192.168.10.100, timeout is 2 seconds:
!!!!!!!!!!!!!!!!!!!!
Success rate is 100 percent (20/20), round-trip min/avg/max = 95/99/104 ms

Capture without policy-map applied:

policy-map config and applied:

RP/0/RP0/CPU0:ios#sh run int g0/0/0/0
Tue Mar 17 16:20:49.240 UTC
interface GigabitEthernet0/0/0/0
service-policy output COS0
ipv4 address 172.31.255.1 255.255.255.0

policy-map COS0
class class-default
set cos 0
set dscp 0
!

Capture after PMAP applied:

You can see DSCP changed. Capture done on my client interface (192.168.10.100)

[Giuseppe Tomasicchio]

I added the following commands and now it works

class-map match-any MATCH
match cos 0 1 2 3 4 5 6 7

end-class-map

policy-map COS0
class MATCH
set cos 0
set cos inner 0
!
class class-default
!
end-policy-map

Thanks

[Francesco Molino]

Ok good to know. Normally using class-default it should have matched all traffic as there's no other class-map configured in this policy-map.