QoS/PFC Traffic Class 3 and Traffic Class 7

mbze430 — Sun, 31 Aug 2025 04:11:17 GMT

Since we don't use RoCEv2 or RDMA we really don't need PFC. Instead I would like to "reclaim" TC7 for CoS7 and DSCP 56-63 for that usage.

sw0(dscp-cos-AZURE)# do sh qos maps

Dscp-to-Traffic-Class map 'AZURE' (dscp= d1d2)
d1 : d2 0 1 2 3 4 5 6 7 8 9
-------------------------------------
0 : 00 00 00 00 00 00 00 00 01 01
1 : 01 01 01 01 01 01 02 02 02 02
2 : 02 02 02 02 03 03 03 03 03 03
3 : 03 03 04 04 04 04 04 04 04 04
4 : 05 05 05 05 05 05 05 05 06 06
5 : 06 06 06 06 06 06 07 07 07 07
6 : 07 07 07 07

Enabled on the following interfaces:

Dscp-to-CoS map 'AZURE' (dscp= d1d2)
d1 : d2 0 1 2 3 4 5 6 7 8 9
-------------------------------------
0 : 00 00 00 00 00 00 00 00 01 01
1 : 01 01 01 01 01 01 02 02 02 02
2 : 02 02 02 02 03 03 03 03 03 03
3 : 03 03 04 04 04 04 04 04 04 04
4 : 05 05 05 05 05 05 05 05 06 06
5 : 06 06 06 06 06 06 07 07 07 07
6 : 07 07 07 07



 

sw0(config-cee-map-default)# do show cee maps default 
CEE Map 'default'
Precedence: 1
Remap Fabric-Priority to Priority 0
Remap Lossless-Priority to Priority 0
Priority Group Table
15.0: PFC Disabled
15.1: PFC Disabled
15.2: PFC Disabled
15.3: PFC Disabled
15.4: PFC Disabled
15.5: PFC Disabled
15.6: PFC Disabled
15.7: PFC Disabled
Priority Table
CoS: 0 1 2 3 4 5 6 7
----------------------------------------
PGID: 15.6 15.7 15.5 15.4 15.3 15.2 15.1 15.0
Enabled on the following interfaces:

I was able to reclaim TC3 for lossy traffic but I still can't get TC7.

sw0(conf-if-te-1/0/1-48)# qos dscp-traffic-class AZURE

Error(s):
tengigabitethernet 1/0/1: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map
tengigabitethernet 1/0/2: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map
tengigabitethernet 1/0/3: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map
tengigabitethernet 1/0/4: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map
tengigabitethernet 1/0/5: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map
tengigabitethernet 1/0/6: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map
tengigabitethernet 1/0/7: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map
tengigabitethernet 1/0/8: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map
tengigabitethernet 1/0/9: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map
tengigabitethernet 1/0/10: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map
tengigabitethernet 1/0/11: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map
tengigabitethernet 1/0/12: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map
tengigabitethernet 1/0/13: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map
tengigabitethernet 1/0/14: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map
tengigabitethernet 1/0/15: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map
tengigabitethernet 1/0/16: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map
tengigabitethernet 1/0/17: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map
tengigabitethernet 1/0/18: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map
tengigabitethernet 1/0/19: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map
tengigabitethernet 1/0/20: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map
tengigabitethernet 1/0/21: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map
tengigabitethernet 1/0/22: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map
tengigabitethernet 1/0/23: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map
tengigabitethernet 1/0/24: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map
tengigabitethernet 1/0/25: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map
tengigabitethernet 1/0/26: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map
tengigabitethernet 1/0/27: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map
tengigabitethernet 1/0/28: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map
tengigabitethernet 1/0/29: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map
tengigabitethernet 1/0/30: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map
tengigabitethernet 1/0/31: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map
tengigabitethernet 1/0/32: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map
tengigabitethernet 1/0/33: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map
tengigabitethernet 1/0/34: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map
tengigabitethernet 1/0/35: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map
tengigabitethernet 1/0/36: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map
tengigabitethernet 1/0/37: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map
tengigabitethernet 1/0/38: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map
tengigabitethernet 1/0/39: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map
tengigabitethernet 1/0/40: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map
tengigabitethernet 1/0/41: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map
tengigabitethernet 1/0/42: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map
tengigabitethernet 1/0/43: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map
tengigabitethernet 1/0/44: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map
tengigabitethernet 1/0/45: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map
tengigabitethernet 1/0/46: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map
tengigabitethernet 1/0/47: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map
tengigabitethernet 1/0/48: %%Error : Command not allowed: Outbound TC conflicts with lossless priority or fabric priority Traffic Class in CEE Map

if someone can tell me how to do that? thanks!

Re: QoS/PFC Traffic Class 3 and Traffic Class 7

Tyler_Edwards — Tue, 28 Oct 2025 19:07:55 GMT

Hello @mbze430 , were you able to find a way to reclaim TC7?

Re: QoS/PFC Traffic Class 3 and Traffic Class 7

mbze430 — Wed, 29 Oct 2025 14:43:51 GMT

Unfortunately, no. I couldn't figure it out. Worse off is that I am not sure how to get it to even start QoS normally again. Right now the switch is running with no QoS.

Re: QoS/PFC Traffic Class 3 and Traffic Class 7

Elwin — Tue, 04 Nov 2025 15:06:30 GMT

That error shows up because TC7 is still linked to a lossless or fabric priority group in the current CEE map. Even if PFC is disabled, the switch won’t let you remap it. Edit the CEE map to detach TC7 from that group, apply the changes, then reapply your DSCP to TC configuration, it should work after that.

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QoS/PFC Traffic Class 3 and Traffic Class 7

Re: QoS/PFC Traffic Class 3 and Traffic Class 7

Re: QoS/PFC Traffic Class 3 and Traffic Class 7

Re: QoS/PFC Traffic Class 3 and Traffic Class 7