Network Connectivity Lost - iSCSI Ports

[Marc_P]

Hi

I have an ESX host which is connected to 2 x 10GB switch (Dell N4032) with uplinks to our core switch. The ESXi host is using the 10GB switch for it's VMNetwork (2 ports - 1 on each switch) and also iSCSI traffic (4 Ports - 2 on each switch).

I keep getting the alarm "network connectivity lost" on this host for the vmnic's that are doing the iSCSI data.

I've searched and found about enabling Port Fast on the ports that the iSCSI taffic is using and this has not helped. I also disabled Spanning Tree as a test and this also did not help.

The switches are running the latest firmware. I'm at a loss as to what else to try. The Server is using Broadcom NetXtreme II BCM57810 cards.

Any help much appreciated.

[Jimmy15]

Assuming connections are fine between ESXi and Storage array

> Run this netcat (nc) command to verify that you can reach the iSCSI TCP port (default 3260) on the storage array from the host:

# nc -z target_ip 3260

> make sure if  jumbo frames configured at your side but not on Storage side

Article :

VMware KB: Troubleshooting iSCSI LUN connectivity issues on ESX/ESXi hosts

Regards

Pankaj