Nexus 9k secondary crash after system switchover

[faberlaser]

Hi everyone, I have a problem with my Nexus 9000 architecture in the vPC domain. I have two Nexus joined in one domain and connected to each other with two 10Gbits peer links and a peer keepalive via supervisor with a dedicated management switch. the vPC domain is successful and synchronized.

To test failover between switches, after a "system switchover" the secondary peer crashes and reboots and activates the second supervisor. On the primary peer everything is fine by changing the active supervisor without restarting the switch. I would like to understand why this happens if it is normal or is a bad configuration. Below is my configuration:

N9K_A:

vrf context management

vpc domain 400
  role priority 100
  peer-keepalive destination 1.1.1.10 source 1.1.1.9
  delay restore 10
  peer-gateway
  track 10

interface port-channel1
  description *** Link to NEXUS_9500K_B ***
  switchport
  switchport mode trunk
  spanning-tree port type network
  vpc peer-link

interface mgmt0
  speed 100
  duplex full
  vrf member management
  ip address 1.1.1.9/24

N9K_B:

vrf context management

vpc domain 400
  role priority 200
  peer-keepalive destination 1.1.1.9 source 1.1.1.10
  delay restore 10
  peer-gateway
  track 10

interface port-channel1
  description *** Link to NEXUS_9500K_A ***
  switchport
  switchport mode trunk
  spanning-tree port type network
  vpc peer-link

interface mgmt0
  speed 100
  duplex full
  vrf member management
  ip address 1.1.1.10/24

NEXUS_9K_A# sh vpc brief
Legend:
                (*) - local vPC is down, forwarding via vPC peer-link

vPC domain id                     : 400
Peer status                       : peer adjacency formed ok     
vPC keep-alive status             : peer is alive                
Configuration consistency status  : success
Per-vlan consistency status       : success                      
Type-2 consistency status         : success
vPC role                          : primary                      
Number of vPCs configured         : 0  
Track object                      : 10 
Peer Gateway                      : Enabled
Dual-active excluded VLANs        : -
Graceful Consistency Check        : Enabled
Auto-recovery status              : Disabled
Delay-restore status              : Timer is off.(timeout = 10s)
Delay-restore SVI status          : Timer is off.(timeout = 10s)
Operational Layer3 Peer-router    : Disabled

Regards

Fabio

[faberlaser]

this is the crash log:

EXUS_9K_B_Gra# 2018 Jan 22 15:55:59 NEXUS_9K_B_Gra %$ VDC-1 %$ %VPC-2-PEER_KEEP_ALIVE_RECV_FAIL: In domain 400, VPC peer keep-alive receive has failed
2018 Jan 22 15:55:59 NEXUS_9K_B_Gra %$ VDC-1 %$ %SYSMGR-2-SERVICE_CRASHED: Service "vpc" (PID 25396) hasn't caught signal 11 (core will be saved).
2018 Jan 22 15:56:01 NEXUS_9K_B_Gra %$ VDC-1 %$ %SYSMGR-2-SERVICE_CRASHED: Service "vpc" (PID 28407) hasn't caught signal 11 (core will be saved).
2018 Jan 22 15:56:03 NEXUS_9K_B_Gra %$ VDC-1 %$ %SYSMGR-2-SERVICE_CRASHED: Service "vpc" (PID 28433) hasn't caught signal 11 (core will be saved).