In order to correctly use beacon fail-over probing for Vmware vSphere server network connectivity you need:

• 2 physical uplink switches in failover set-up;
• 3 physical uplinks in team per each vSwitch with beacon probing enabled;
• 2 of the uplinks (each going into different uplink switch) must be active and the third physical uplink should be set-up as a Standby adapter.

Beacon probing also works if you are using Vlan trunks. The only difference is that in case of any uplink failure beacon probes will be sent to all vSwitch VLANs increasing traffic a little.

Keep in mind:

You cannot advertise one MAC address to different uplink physical switches or Network flapping may occur. Do not use Beacon probing Network failover detection if you are using IP Hash Load balancing. Use IP Hash load balancing only with Etherchannel.

Popular sites receive high concurrent web visitor requests and some clients send bad favicon.ico fetch requests. If you are running nginx you probably didn’t notice that, for example: /category/favicon.ico generate significant 404 errors in your server error log file, because this file is located only in root, e.g. /favicon.ico.

Every request for non-existent file takes some load and every 404 missing file error is usually logged into error_log file, unless you have disabled error logging. To forward all non-root favicon.ico requests to /favicon.ico you can set-up the following rewrite rule in nginx.conf file in the correct server{} location:

rewrite ^/(.*)/favicon.ico$ /favicon.ico last;

Voila. Restart the nginx daemon and you will see slightly decreased load on your box.