QoS DSCP EF with 3750-X

[pboegli77]

Hi,

I'm testing QoS with a 3750-X

I want to mark traffic in the 192.168.126.0/24 subnet with DSCP EF.

I've entered this command :

mls qos

class-map match-any class_126

  match access-group 2

policy-map mark_dscp_126

class class_126

   set dscp ef

access-list 2 permit 192.168.126.0 0.0.0.255

And I affect this policy to port 8 :

service-policy input mark_dscp_126

I've a PC on port 8 with IP 192.168.126.1 and I'm doing an iperf test with an other PC :

Without policy :

[ ID] Interval       Transfer     Bandwidth

[  4]  0.0- 3.0 sec   273 MBytes   763 Mbits/sec

[  4]  3.0- 6.0 sec   276 MBytes   772 Mbits/sec

[  4]  6.0- 9.0 sec   275 MBytes   770 Mbits/sec

[  4]  0.0-10.0 sec   916 MBytes   768 Mbits/sec

With policy :

[  4]  0.0- 3.0 sec  15.1 MBytes  42.3 Mbits/sec

[  4]  3.0- 6.0 sec  13.6 MBytes  37.9 Mbits/sec

[  4]  6.0- 9.0 sec  12.5 MBytes  35.1 Mbits/sec

[  4]  0.0-10.3 sec  46.1 MBytes  37.7 Mbits/sec

Why bandwith is limited when traffic is marked ?

[pboegli77]

When I mark traffic with DSCP AF11, there is no problem...

I'v a high bandwith...

[Marwan ALshawi]

Is there any shaping applied on the interface

Can you post the interface config

[pboegli77]

No shaping...

interface GigabitEthernet1/0/8

switchport trunk encapsulation dot1q

switchport trunk allowed vlan 8,62,120,122-126,128,129,172

switchport mode trunk

service-policy input mark_dscp_126

Ans also :

gw_c3750_ma_01#sh mls qos input-queue

Queue     :       1       2

----------------------------------------------

buffers   :      90      10

bandwidth :       4       4

priority  :       0      10

threshold1:     100     100

threshold2:     100     100

gw_c3750_ma_01#sh mls qos queue-set

Queueset: 1

Queue     :       1       2       3       4

----------------------------------------------

buffers   :      25      25      25      25

threshold1:     100     200     100     100

threshold2:     100     200     100     100

reserved  :      50      50      50      50

maximum   :     400     400     400     400

Queueset: 2

Queue     :       1       2       3       4

----------------------------------------------

buffers   :      25      25      25      25

threshold1:     100     200     100     100

threshold2:     100     200     100     100

reserved  :      50      50      50      50

maximum   :     400     400     400     400

Thank you

[Edison Ortiz · Accepted solution]

Did you enter 'priority-queue out' under all interfaces?

[pboegli77]

Thank you, with "priority-queue out", the bandwith is high again