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  • 1.  Strange network issue when ESX servers powered on

    Posted Dec 15, 2015 12:32 PM


    Firstly, not sure if this is the right forum but hope you can help.

    I have a issue where randomly the firewall stops responding for a small number or random hosts/pcs/physical server on my network. This problem has started since the introduction of VMware and two ESX servers. I think its an ARP issue as clearing the NIC ARP cache on the windows machine that has the trouble fixes the problem temporarily. A permeant fix is to shut off the ESX servers, which is obviously not a fix.

    Ive changed the firewall incase its that but have same issue. Any thoughts on what to check on ESX to see whats causing it? My ESX servers currently have a single NIC on the LAN vSwitch for simplicity and a separate vSwitch for 10gb iSCSI which is direct connected to the SAN. Very simple.


  • 2.  RE: Strange network issue when ESX servers powered on
    Best Answer

    Posted Dec 15, 2015 02:14 PM

    Ive found my issue.

    My SAN, a HP MSA2040 runs a 192.168.200.x network for internal use according to HP support. Even though id changed the management IP to another network it stills runs this range. Consequently the card was updating ARP tables and sending some hosts network request to the wrong MAC/IP which just happened to be the IP of my gateway. Crazy stuff.