Lan Bypass; Figure 17: Connectivity Options Of Lan Ports In A Bypass Segment - Advantech FWA-5020 User Manual

initiate a rollback when the BIOS is found to be corrupted.
The BIOS watchdog timeout is set to a predefined value of 300 seconds and
automatically starts when the payload power for the x86 subsystem is being turned
on or when a x86 reset is detected. The time out action is set to Hard Reset, with the
timer use indicating BIOS FRB2 use.
If the watchdog timer times out with this configuration, it triggers a BIOS chip failover
followed by a system reset and a restart of the watchdog timer.
The BIOS does not touch the watchdog timer except the following situations:
1. It disables the watchdog right before jumping into the x86 OS boot loader so it
doesn't trigger after BIOS execution. It could alternatively reconfigure the watchdog
to act as boot watchdog (i.e. change timeout action), based on BIOS configuration.
2. It temporarily disables the watchdog once the BIOS setup menu is entered, so the
watchdog does not trigger while the user is in the BIOS menu.

2.5.3 LAN Bypass

For a detailed description of the LAN Bypass functionality and the related software
API, please refer to the Advanced LAN Bypass User's Manual.
LAN bypass allows automated or manual control of the connectivity between two
LAN ports grouped into a bypass segment and the host:

Figure 17: Connectivity options of LAN ports in a bypass segment

In "connect" mode, the ports on a segment are connected to the host via NICs.
Traffic will enter and leave the ports just like on a regular NIC.
In "disconnect" mode, the ports are disconnected from the host and from each other.
No traffic can flow through the ports
In "bypass" mode, the two ports are disconnected from the host, but connected to
each other. Traffic entering the system on one port will be sent out on the other port
and vice versa.
"Bypass mode" is used to allow traffic to flow through the system when the system is
in a non operational state such as loss of power or in case the application is
unresponsive. Application health is monitored by a configurable watchdog.
_20161111
FWA-5020 User Manual v01 Copyright 2015 Advantech Co. Ltd. All rights reserved. Page 44