Today in our Vmware env, I have found one of VMware ESXi host lost communication to the Cisco Nexus dvswitch, and all of the VMs were running on the ESXi would have lost connections to network as well.
The network team checked the blade switch and can see the physical connections are up during the downtime between the ESXi and Cisco Nexus switch.
Both the Physical NICs assigned for the dvSwitch i.e. VMNIC2 & VMIC3 are showing down for that ESXi host.
I tried to manually change the speed of the NIC and also tried to bring up the NICs manually but nothing helped. Can you please
help me in checking what may be the cause for this issue.
We have had this issue previously as well. The most helpfull tool I used was to log into the esxi host that was offending and from the command line run vmkping to see what the results were. Check out the options to vmkping not only to other hosts but other nics on the same host to check for connectivity. Ultimately we had a host loosing redundancy and removing the nic from the motherboard and adding a new one was our fix.
Thanks a lot for your reply Aaron, here the issue got resolved when I reboot the effected ESXi host and then I found that both the Uplinks were UP & running fine, but the issue here is to get the root cause as why suddenly both the Uplinks went down and the network team investigated from Cisco Nexus point of view and found no issues at their end.