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| Affected Product Name | Description | Comments |
|---|---|---|
| N540-24Q2C2DD-SYS | NCS540-2x400G QSFP-DD+2x100G+24x25G | |
| N540-24Q8L2DD-SYS | NCS540-2x400G QSFP-DD+8x50G+24x25G |
| Defect ID | Headline |
| CSCwq28776 | N540-24Q8L2DD Arches Intermitten BIT flips causiing pkt Corruption. |
Some Cisco Network Convergence System (NCS) 540 Series Routers with product IDs N540-24Q8L2DD-SYS and N540-24Q2C2DD-SYS may exhibit packet drop errors.
A change in the component vendor's recommended operating values caused this issue. It has now been fixed, and devices shipping from manufacturing are equipped with correct voltage parameters.
Routers with product IDs N540-24Q8L2DD-SYS and N540-24Q2C2DD-SYS that are affected by the packet drop issue can be validated using the show environment voltage CLI command, as shown in the following example.
RP/0/RP0/CPU0:ios#show environment voltage
DDD MM DD HH:MM:SS UTC
Location: /RP0/CPU0
Sensor Value (mV) Crit (Lo) Minor (Lo) Minor (Hi) Crit (Hi)
VH1_P12V 12486 10560 10800 13200 13440
VP8_METADX_AVDD_0V8 813 765 790 838 863
VP9_P1V0_IOFPGA 997 940 970 1030 1060
VP10_P1V8_IOFPGA 1805 1692 1746 1854 1908
VP11_P2V5 2507 2350 2425 2575 2650
VP12_P3V3 3308 3102 3201 3399 3498
VP13_P1V8 1797 1692 1746 1854 1908
VH1_CPU_12V 12501 10560 10800 13200 13440
VH4_CPU_5V_SDTBY 5008 4700 4850 5150 5300
VH2_GDDR6_1V25 1297 1222 1261 1339 1378
VP1_CPU_1V2_SDTBY 1207 1140 1164 1236 1272
VP2_CPU_2V5_SDTBY 2515 2375 2425 2575 2650
VP3_CPU_3V3_SDTBY 3299 3135 3201 3416 3465
VP4_CPU_CORE_1V82 1786 1602 1711 1875 1966
VP5_CPU_PCH_1V5 1494 1425 1455 1545 1590
VP6_CPU_DDR_VTT_0V6 597 558 582 618 642
VP7_CPU_DDR_1V2 1195 1140 1164 1236 1275
VP8_CPU_2V5 2498 2375 2425 2575 2750
VP9_CPU_1V05 1047 987 1019 1076 1092
VP10_CPU_1V3 1295 1235 1261 1339 1378
VH3_GDDR6VPP_1V8 1799 1692 1746 1854 1908
VP11_CPU_1V7 1694 1615 1649 1751 1802
VP12_CPU_3V3 3301 3168 3218 3399 3465
P1V8_Q2A_VOUT 1794 1692 1746 1854 1908
P1V25_Q2A_VOUT 1291 1222 1261 1339 1378
VH4_02A_0V88 880 836 854 898 915
P0V82_Q2A_VOUT 720 707 722 927 977
P1V8_VOUT 1800 1692 1746 1854 1908
VP1_Q2A_XVDD1P8 1799 1692 1746 1854 1908
P3V3_VOUT 3304 3135 3201 3416 3465
P0V8_Q2A_SRDS_VOUT 801 752 776 824 848
VP2_02A_TVDD1P2 1198 1128 1152 1236 1260
P0V8_METDX1_VOUT 777 733 757 824 848
VP3_Q2A_XVDD0P8 799 760 772 828 836
P1V82_CPU_CORE_VOUT 1787 1692 1746 1854 1908
P1V2_CPU_VOUT 1197 1140 1164 1236 1275
VP4_Q2A_VDCC_0V82 718 707 722 927 977
P1V05_CPU_VOUT 1050 987 1019 1076 1092
VP5_METADX_0V8 785 733 757 824 848
The voltage output of P0V82_Q2A_VOUT and VP4_02A_VDCC_0V82 of 718 and 720 in the example indicates the failure signature described in this field notice.The voltage output of less than 760 can be considered as failure signature of the issue described in the field notice.
Cisco recommends installing the SMU listed in the following table for routers that are deployed with Cisco IOS XR Software Releases. The fix is incorporated into base Cisco IOS XR Software releases 25.2.2 and later.
| Cisco IOS XR Software Release | SMU Type | SMU Status | SMU Download Instructions |
|---|---|---|---|
| 7.11.2 | Reload | Posted |
|
| 24.4.2 | Reload | Posted | |
| 24.3.2 | Reload | Posted | |
| 24.2.2 | Reload | Posted | |
| 24.1.2 | Reload | Posted |
Cisco does not recommend RMA for the issue observed as the issue can be fixed with the solution provided.
| Version | Description | Section | Date |
| 1.0 | Initial Release | — | 2026-JAN-15 |
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