Symptom

After having a kernel crash in the switch we are seeing almost 12sec delay for the peer to bring down its link for EX platforms. The time calculated is when the crash is initiated in the local switch for a module to the time when the peer device brought its link down connected to this crashed module. Tahoe# show module Mod Ports Module-Type Model Status --- ----- ------------------------------------- --------------------- --------- 2 52 48x10/25G + 4x40/100G Ethernet Module N9K-X97160YC-EX ok 3 36 36x100G Ethernet Module N9K-X9736C-EX ok 22 0 4-slot Fabric Module N9K-C9504-FM-E ok 23 0 4-slot Fabric Module N9K-C9504-FM-E ok 24 0 4-slot Fabric Module N9K-C9504-FM-E ok 25 0 4-slot Fabric Module N9K-C9504-FM-E powered-dn 26 0 4-slot Fabric Module N9K-C9504-FM-E ok 27 0 Supervisor Module N9K-SUP-A active * 29 0 System Controller N9K-SC-A standby 30 0 System Controller N9K-SC-A active Crash for module 2 [N9K-X97160YC-E] =============================== 2020 Dec 24 10:59:42.215 Tahoe %PLATFORM-1-PFM_ALERT: Module 2 has experienced a kernel panic. 2020 Dec 24 10:59:53.543 Tahoe %KERN-0-SYSTEM_MSG: [ 4193.651665] EMON: module 2 is not responding on EOBC path. Reloading module. - kernel 2020 Dec 24 10:59:54.219 Tahoe %MODULE-2-MOD_DIAG_FAIL: Module 2 (Serial number: FOC233195HZ) reported failure due to EOBC heartbeat failure in device DEV_EOBC_MAC (device error 0xc0a1b137) 2020 Dec 24 10:59:54.379 Tahoe %ETHPORT-5-IF_DOWN_MODULE_REMOVED: Interface Ethernet2/1 is down (module removed) 2020 Dec 24 10:59:53.114 peer %ETHPORT-5-IF_DOWN_LINK_FAILURE: Interface Ethernet1/4 is down (Link failure) >>>>>>>>>>>>>>>>This log message is from peer Crash for module 3 [N9K-X9736C-EX] ============================== 2020 Dec 23 16:37:07.706 Tahoe %PLATFORM-1-PFM_ALERT: Module 3 has experienced a kernel panic. 2020 Dec 23 16:37:19.920 Tahoe %KERN-0-SYSTEM_MSG: [98946.020914] EMON: module 3 is not responding on EOBC path. Reloading module. - kernel 2020 Dec 23 16:37:20.334 Tahoe %MODULE-2-MOD_DIAG_FAIL: Module 3 (Serial number: FOC23351HVW) reported failure due to EOBC heartbeat failure in device DEV_EOBC_MAC (device error 0xc0a1b137) 2020 Dec 23 16:37:20.455 Tahoe %ETHPORT-5-IF_DOWN_INTERFACE_REMOVED: Interface Ethernet3/4 is down (Interface removed) 2020 Dec 23 16:37:19.233 peer %ETHPORT-5-IF_DOWN_LINK_FAILURE: Interface Ethernet1/6 is down (Link failure) >>>>>>>>>>>>>>>>This log message is from peer

Conditions

Kernal crash

Workaround

NA

Further Problem Description