Proxy Failure Detection (TCP keepalive)

The ESX Server uses a TCP keepalive timer to determine if a serial port connection between a virtual machine and a virtual serial port proxy is still active. By default, the virtual serial port keepalive time is 300 seconds.
To configure the keepalive time for a serial port connection, set the
keepIdle
advanced option for the virtual machine. The option name uses the following format:
serial
n
.keepIdle
n
is an integer in a sequence starting with zero, corresponding to the sequence of serial ports on the virtual machine. Examples of
keepIdle
options include
serial0.keepIdle
,
serial1.keepIdle
, and
serial2.keepIdle
.
The
keepIdle
value is the duration in seconds on an idle connection, after which the ESX Server sends up to five keepalive probes to the virtual serial port proxy. If there is no response after five probes, the connection is considered inactive. The Server uses a keepalive interval of 1/100th of the
keepIdle
value, and a retry value of five. Using the default
keepIdle
value (300 seconds), the Server will detect a proxy failure no later than 315 seconds after the last activity (300 + 5*300/100).