Symptom

Interface stays down with BER alarm and "PCS Lane BIP Errors" are high and seen continuously on the interface. `show controllers {affected_interface} phy` CLI will show BIP errors continously on the link. Example: RP/0/RSP0/CPU0:XR#show controllers HundredGigE 0/2/0/1 phy PHY data for interface: HundredGigE0/2/0/1 *** PHY PCS PMA Statistics *** Rx Rx Aligment PCS PCS Service Block Marker Lane Lane Lane Lock Lock BIP Errors Mapping ------- --------- --------- ---------- ------- 0 Locked Locked 119248 6 1 Locked Locked 119290 12 2 Locked Locked 119281 18 3 Locked Locked 9133493 10 4 Locked Locked 9116939 11 5 Locked Locked 9149875 3 6 Locked Locked 119305 13 7 Locked Locked 9152346 8 8 Locked Locked 9152637 9 9 Locked Locked 9151467 14 10 Locked Locked 9151982 4 11 Locked Locked 9127412 5 12 Locked Locked 119263 0 13 Locked Locked 119275 1 14 Locked Locked 9147983 15 15 Locked Locked 9152247 7 16 Locked Locked 119328 17 17 Locked Locked 119291 2 18 Locked Locked 119283 19 19 Locked Locked 119281 16 SI setting is observed to be incorrect. An SI value of 0x1 is expected. `lda_test client cpak read {port_number} {0x1a440|0x1a441|0x1a442|0x1a443}` will indicate the current "Value". Note: This command is only available if MPA is placed in BAY0. Example: run ssh lc_xr (eXR) or run attach [xr-vm_node0__CPU0:~]$lda_test client cpak read 1 0x1a440 CPAK: Port 1 Register = 0x0001a440 Value = 0x00000007 Read rc = 0x00000000 [xr-vm_node0__CPU0:~]$lda_test client cpak read 1 0x1a441 CPAK: Port 1 Register = 0x0001a441 Value = 0x00000007 Read rc = 0x00000000 [xr-vm_node0__CPU0:~]$lda_test client cpak read 1 0x1a442 CPAK: Port 1 Register = 0x0001a442 Value = 0x00000007 Read rc = 0x00000000 [xr-vm_node0__CPU0:~]$lda_test client cpak read 1 0x1a443 CPAK: Port 1 Register = 0x0001a443 Value = 0x00000007 Read rc = 0x00000000 If BER thresholds are caused LAN-SF-BER and LAN-SD-BER faults can be seen. `show controller {affected_internal} internal` will show these faults.

Conditions

CPAK-100G-LR4 paired with CVR-CFP2-CPAK4 and connected on A9K-MPA-2X100GE

Workaround

The TX emphasis can be set manually but OIR/reloads will reset the SI value. Commands for manual program. - run ssh lc_xr (eXR) or run attach - lda_test client cpak write 0x1a440 0x1 lda_test client cpak write 0x1a441 0x1 lda_test client cpak write 0x1a442 0x1 lda_test client cpak write 0x1a443 0x1 Limitation : This works only on bay 0 optics.

Further Problem Description