Symptom
Link between the punt switch and NPU intermittently stays down. This cause NPU loopback Test fails and ARP do not get resolve.
Conditions
This issue observed post LC boot up. Not seen on run state.
Workaround
This issue seen following LC boot up, second LC reload recovers the link.
Further Problem Description
sysadmin-vm:0_RP0# show controller switch statistics location 0/LC9/LC-SW | inc Down
21 Down 0 0 0 0 0 NP1
NPU loopback Test also fails when this issue occurs.
LC/0/19/CPU0:Jan 19 04:40:59.561 UTC: pfm_node_lc[300]: %PLATFORM-DIAGS-0-LC_NP_LOOPBACK_FAILED_TX_PATH : Set|online_diag_lc[6041]|Line card NPU loopback Test(0x2000006)|link failure mask is 0x8.
LC/0/9/CPU0:Jan 19 04:41:58.473 UTC: pfm_node_lc[232]: %PLATFORM-DIAGS-0-LC_NP_LOOPBACK_FAILED_TX_PATH : Set|online_diag_lc[6027]|Line card NPU loopback Test(0x2000006)|link failure mask is 0x2.
