Installation guide

CHAPTER 11 Networking
377
the failure threshold will the server identify a link as disconnected and switch to
another adapter.
By default, the beacon failure threshold is set to zero for each virtual switch. You can
enable beacon monitoring by setting the failure threshold to two or greater.
ESX Server also allows you to determine the frequency with which it issues beacons.
The rate at which the server broadcasts beacons, in conjunction with the failure
threshold, determines the total monitoring interval before the server identifies a link
as isolated:
Beacon Interval (in seconds) X Beacon Failure Threshold = Total Beacon Failure
Interval
You set the failure threshold for an individual switch with the
switch_failover_threshold option. This example describes how to set the
failure threshold for bond1 to 2 beacons:
1. Log into the Service Console as root.
2. Edit /etc/vmware/hwconfig.
3. Set the beacon failure threshold for bond1:
nicteam.bond1.switch_failover_threshold = “2”
4. Save the file and close it.
ESX server broadcasts beacons with the same frequency for all switches. The
SwitchFailoverBeaconInterval option sets this value. The server also defines an
overall failure threshold for all switches with the SwitchFailoverThreshold option, but
switch_failover_threshold overrides this value for each individual switch.
You can set the values of the SwitchFailoverBeaconInterval and
SwitchFailoverThreshold options in the Advanced Settings panel of the
Management Interface. See Changing Advanced Settings on page 242 for details.
Beacon monitoring can cause false indications of network connection failure. External
switches may trap beacon packets, causing ESX Server to declare a switch failure for a
connection that is functioning normally. When the the server switches to a secondary
link, traffic from the primary may still be transmitted because the connection has not
actually failed. This can result in an external switch receiving duplicate packets from
both links.
Note: ESX Server uses beacon monitoring as a secondary method to detect network
failures. When the server detects a physical link failure for the primary adapter, it will
switch to a secondary adapter without regard to whether beacon monitoring
indicates a failed connection.