[GCU][202405] Same rx drop counters are seen on a different port(not part of test) as the PCH-port added via GCU. #24745
Description
Is it platform specific
broadcom
Importance or Severity
Critical
Description of the bug
Following configuration is added via GCU in 2 patch format:
1st patch:
- speed and lane change.
- Port-channel interface, and member configuration. (Pprt-channel has single port and min_links set to 1 for the test purpose).
- cable-length.
- PFCWD and PORT_QOS_MAP configuration.
2nd patch:
- scheduler configuration.
We are trying to add 8 ports via GCU with 4 in each ASIC.
Note: I am not sure if this issue can be reproduced without GCU or not. I was able to consistently reproduce the same with GCU and hence tagging GCU. I have not tried to reproduce the same without GCU.
We are running snappi m2o oversubscription testcase. In this testcase, we have 2 ingresses sending more traffic than egress, thus causing drop of lossy traffic on the ingress.
This causes Tx drops on both ingress ports. However, the tx_drop counter (seen via show interface counter) is also incremented (and is exactly same) for a different port which is not part of the test at all.
Seen below, Ethernet40 is has RX_DRP of 5,736,150. However, Ethernet16 is also reporting same RX_DRP, although it is not even UP.
admin@ixre-egl-board74:~$ show interface counter
Last cached time was 2025-12-04T14:29:21.892248
IFACE STATE RX_OK RX_BPS RX_UTIL RX_ERR RX_DRP RX_OVR TX_OK TX_BPS TX_UTIL TX_ERR TX_DRP TX_OVR
----------- ------- ---------- ----------- --------- -------- --------- -------- ----------- ----------- --------- -------- -------- --------
Ethernet0 U 0 0.00 B/s 0.00% 0 0 0 36 144.21 B/s 0.00% 0 0 0
Ethernet8 X 0 0.00 B/s 0.00% 0 0 0 0 0.00 B/s 0.00% 0 0 0
Ethernet16 X 0 0.00 B/s 0.00% 0 5,736,150 0 0 0.00 B/s 0.00% 0 0 0
Ethernet24 X 0 0.00 B/s 0.00% 0 0 0 0 0.00 B/s 0.00% 0 0 0
Ethernet32 X 0 0.00 B/s 0.00% 0 0 0 0 0.00 B/s 0.00% 0 0 0
Ethernet40 U 65,852,497 297.94 MB/s 2.38% 0 5,736,150 0 8 12.04 B/s 0.00% 0 0 0
Ethernet48 X 0 0.00 B/s 0.00% 0 0 0 0 0.00 B/s 0.00% 0 0 0
Ethernet56 X 0 0.00 B/s 0.00% 0 0 0 0 0.00 B/s 0.00% 0 0 0
Ethernet64 X 0 0.00 B/s 0.00% 0 0 0 0 0.00 B/s 0.00% 0 0 0
Ethernet72 X 0 0.00 B/s 0.00% 0 0 0 0 0.00 B/s 0.00% 0 0 0
Ethernet80 U 65,852,497 297.91 MB/s 2.38% 0 5,736,151 0 8 29.95 B/s 0.00% 0 0 0
Ethernet88 U 0 0.00 B/s 0.00% 0 0 0 37 156.24 B/s 0.00% 0 0 0
Ethernet96 X 0 0.00 B/s 0.00% 0 0 0 0 0.00 B/s 0.00% 0 0 0
Ethernet104 X 0 0.00 B/s 0.00% 0 0 0 0 0.00 B/s 0.00% 0 0 0
Ethernet112 U 7 8.93 B/s 0.00% 0 0 0 120,232,688 546.32 MB/s 4.37% 0 0 0
The output of 'show interface status' shows that Ethernet16 is still 400Gbps port, not part of any port-channel, and is down.
admin@ixre-egl-board74:~$ show interface status
Interface Lanes Speed MTU FEC Alias Vlan Oper Admin Type Asym PFC
--------------- ------------------------------- ------- ----- ----- ------------ --------------- ------ ------- ----------------------------------------------- ----------
Ethernet0 72,73,74,75,76,77,78,79 400G 9100 N/A Ethernet1/1 PortChannel1013 up up QSFP-DD Double Density 8X Pluggable Transceiver off
Ethernet8 80,81,82,83,84,85,86,87 400G 9100 N/A Ethernet2/1 routed down down QSFP-DD Double Density 8X Pluggable Transceiver off
Ethernet16 88,89,90,91,92,93,94,95 400G 9100 N/A Ethernet3/1 routed down down N/A off
Ethernet24 96,97,98,99,100,101,102,103 400G 9100 N/A Ethernet4/1 routed down down N/A off
Ethernet32 104,105,106,107,108,109,110,111 400G 9100 N/A Ethernet5/1 routed down down N/A off
Ethernet40 112,113,114,115 100G 9100 none Ethernet6/1 PortChannel1016 up up QSFP28 or later off
Ethernet48 120,121,122,123,124,125,126,127 400G 9100 N/A Ethernet7/1 routed down down N/A off
Ethernet56 128,129,130,131,132,133,134,135 400G 9100 N/A Ethernet8/1 routed down down N/A off
Ethernet64 136,137,138,139,140,141,142,143 400G 9100 N/A Ethernet9/1 routed down down N/A off
Ethernet72 64,65,66,67,68,69,70,71 400G 9100 N/A Ethernet10/1 routed down down N/A off
Ethernet80 56,57,58,59 100G 9100 none Ethernet11/1 PortChannel1018 up up QSFP28 or later off
Ethernet88 48,49,50,51 100G 9100 none Ethernet12/1 PortChannel1015 up up QSFP28 or later off
Ethernet96 40,41,42,43,44,45,46,47 400G 9100 N/A Ethernet13/1 routed down down N/A off
Ethernet104 32,33,34,35,36,37,38,39 400G 9100 N/A Ethernet14/1 routed down down N/A off
Ethernet112 24,25,26,27 100G 9100 none Ethernet15/1 PortChannel1017 up up QSFP28 or later off
Ethernet120 16,17,18,19,20,21,22,23 400G 9100 N/A Ethernet16/1 routed down down N/A off
Ethernet128 8,9,10,11,12,13,14,15 400G 9100 N/A Ethernet17/1 routed down down N/A off
Ethernet136 0,1,2,3,4,5,6,7 400G 9100 N/A Ethernet18/1 routed down down N/A off
Ethernet144 72,73,74,75,76,77,78,79 400G 9100 N/A Ethernet19/1 PortChannel1014 up up QSFP-DD Double Density 8X Pluggable Transceiver off
Ethernet152 80,81,82,83,84,85,86,87 400G 9100 N/A Ethernet20/1 routed down down N/A off
Ethernet160 88,89,90,91,92,93,94,95 400G 9100 N/A Ethernet21/1 routed down down N/A off
Ethernet168 96,97,98,99,100,101,102,103 400G 9100 N/A Ethernet22/1 routed down down N/A off
Ethernet176 104,105,106,107,108,109,110,111 400G 9100 N/A Ethernet23/1 routed down down N/A off
Ethernet184 112,113,114,115,116,117,118,119 400G 9100 N/A Ethernet24/1 routed down down N/A off
Ethernet192 120,121,122,123,124,125,126,127 400G 9100 N/A Ethernet25/1 routed down down N/A off
Ethernet200 128,129,130,131 100G 9100 none Ethernet26/1 PortChannel1020 up up QSFP28 or later off
Ethernet208 136,137,138,139,140,141,142,143 400G 9100 N/A Ethernet27/1 routed down down N/A off
Ethernet216 64,65,66,67,68,69,70,71 400G 9100 N/A Ethernet28/1 routed down down N/A off
Ethernet224 56,57,58,59 100G 9100 none Ethernet29/1 PortChannel1022 up up QSFP28 or later off
Ethernet232 48,49,50,51 100G 9100 none Ethernet30/1 PortChannel1019 up up QSFP28 or later off
Ethernet240 40,41,42,43,44,45,46,47 400G 9100 N/A Ethernet31/1 routed down down N/A off
Ethernet248 32,33,34,35,36,37,38,39 400G 9100 N/A Ethernet32/1 routed down down N/A off
Ethernet256 24,25,26,27,28,29,30,31 400G 9100 N/A Ethernet33/1 routed down down N/A off
Ethernet264 16,17,18,19,20,21,22,23 400G 9100 N/A Ethernet34/1 routed down down N/A off
Ethernet272 8,9,10,11 100G 9100 none Ethernet35/1 PortChannel1021 up up QSFP28 or later off
Ethernet280 0,1,2,3,4,5,6,7 400G 9100 N/A Ethernet36/1 routed down down N/A off
PortChannel1013 N/A 400G 9100 N/A N/A routed down up N/A N/A
PortChannel1014 N/A 400G 9100 N/A N/A routed down up N/A N/A
PortChannel1015 N/A 100G 9100 N/A N/A routed down up N/A N/A
PortChannel1016 N/A 100G 9100 N/A N/A routed up up N/A N/A
PortChannel1017 N/A 100G 9100 N/A N/A routed up up N/A N/A
PortChannel1018 N/A 100G 9100 N/A N/A routed up up N/A N/A
PortChannel1019 N/A 100G 9100 N/A N/A routed down up N/A N/A
PortChannel1020 N/A 100G 9100 N/A N/A routed down up N/A N/A
PortChannel1021 N/A 100G 9100 N/A N/A routed down up N/A N/A
PortChannel1022 N/A 100G 9100 N/A N/A routed down up N/A N/A
I was seeing same behavior for port Ethernet160 reflecting same Rx_DRP counters as Ethernet200 in asic1.
Tagging @saksarav-nokia @rawal01 @mlok-nokia @snider-nokia
Steps to Reproduce
I have not tried reproducing this issue without GCU. With GCU, I was able to reproduce this and hence giving steps here:
- Add port with speed-lane change + PCH + PCH IP config + BGP configuration + PFC_WD + PORT_QOS_MAP.
- Add scheduler configuration.
Send traffic through the ports added so that ingress is oversubscribed and has drops. Check other ports for RX_DRP counter incrementing incorrectly.
Actual Behavior and Expected Behavior
The counters for any other port, which is not part of test, and port-channel should not increment.
Relevant log output
Output of show version, show techsupport
Attach files (if any)
No response