show ports qosmonitor

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  • Updated 3 years ago
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Hi all,

We're implementing QoS on 6 switches - 4 BD8810 and 2 X480, SW version is
The configuration is as follows:

configure vlan <vlan_name> qosprofile qp6
enable diffserv replacement ports <port_list>
configure diffserv replacement qp6 code-point 46

Then we check queues by issuing "show ports <port_list> qosmonitor
The interesting thing is that on all BD we see counters incrementing in real-time for QP1 and QP6 as it should be.
But on both X480 despite the same configuration while typing the same command we see only QP1 counters increment while QP6 counters increase only once right after enabling diffserv replacement.
I experimented - cleared the counters and issued "enable diffserv replacement" once again, then checked counters - they again increased only once (some small numbers like 100 packets) and then stop.

I tried to configure diffserv examination on uplink ports but it didn't change the indication of qosmonitor.
Also tried the same on old X450 with 11 version - but the result was the same - it didn't show the increase in QP6.

Have anyone faced the same?
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Eugene Lupashko

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Posted 3 years ago

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Paul Russo, Alum

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Hey Eugene

This is most likely do to the fact that VLAN and Diffserv examination are on the lower side of the precedence order for QoS.

see here

"BlackDiamond X8 series switches, BlackDiamond 8800  Series Switches, SummitStack, and Summit Family"
"1        ACL-based traffic groups for IP packets  (specifies IP address  information)"
"2    ACL-based traffic groups for Ethernet  frames (specifies MAC address  information)"
"3    CoS 802.1p-based  traffic groups"
"4    Port-based traffic groups"
"5    VLAN-based traffic groups"
"6    DiffServ-based traffic groups"

If the packet going into the 480 is tagged then .1p will take precedence and will be handled before Diff-Serv examination will. 

.1p examination is enabled by default.  So test this and work around it you can disable .1p examination and then Diff-Serv will take over or you can use an ACL to look at the DSCP then put it in the correct Queue.  ACLs have the highest precedence

Let us know what you find out.

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Eugene Lupashko

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Hi Paul,

Thank you for advice, I'll try it after the weekend and share results.

Best regards,
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Drew C., Community Manager

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Hi Eugene,
Did Paul's advice help to answer your questions?