Solution for error: "network connectivity lost" and "network uplink redundancy lost

[Beadmin]

Hello,

I was getting the above errors every 2 mins, but I did not find any issues with my network.

I updated my ESXi to latest 5.5 with all updates with no help.

I have reffer to this simple solution of Alarms enabled/disabled, and I am no longer getting this error:

http://www.theoddangryshot.com/2013/11/constant-alarm-network-uplink.html

Can any one confirm me, if my issue is really resolved or do I still need to worry, is their way to double check?

Thanks

[nkrishnan]

This error generally gives only if your uplink goes down, it can either due to physical connection unplugged or packet loss in a certain amount of time. What is the redundant policy that you have set it. Can you try by explicit fail over. This would give a better picture if you really looses the network.

[Gav0]

You should check for port speed/duplex mismatches on your vmnics and physical switch ports.

Make sure the vmnics and the physical switch ports are all set to auto negotiate

[Beadmin]

One of the Nic was on Auto and other not, I changed it to Auto as well, and now errors are back.

Also one of the ISCSI port nic teaming was different to other, I changed it to active-active as well.

[Gav0]

You should also check your switch ports config.  I've seen issues in the past where switch ports are set to 1000/full and ESXi hosts are set to auto and there is some flapping around - both should be set to auto.

If this is a production environment tread very carefully making changes to your storage network.

Can you check the properties of the iscsi initiator and have a look at the 'network configuration' tab - is it showing any warnings under port group policy, or is it compliant?

Looking at your config you should configure it like this providing you are happy the connectivity is set up correct:

ISCSI-1 vmnic2 active, vmnic3 unused

ISCSI-2 vmnic3 active, vmnic2 unused

Check out this short whitepaper on iscsi multipathing as it may help you in troubleshooting further

http://www.vmware.com/files/pdf/techpaper/vmware-multipathing-configuration-software-iSCSI-port-bind...