bypass is a utility to control Failover bypass network adapters.


bypass [interface] status
bypass [interface] open
bypass [interface] close
bypass [interface] set_wdt tmo
bypass [interface] disablewdt
bypass [interface] touch

For all commands, you can optionally specify an interface (device) name. This allows individual control of specific bypass ports, if you have more than 2 bypass ports installed. If no interface is specified, commands are applied to all detected bypass ports. If there is only 1 card in the system, there is no need to specify the interface.


Prints information about the bypass device(s).

# bypass status

Gets status information about all bypass cards in the system.

# bypass igb2 status

Gets status information for the igb2 interface, if it is a bypass NIC.

Sample Output:

stdClass Object
[igb2] => stdClass Object
[media_status] => stdClass Object
[link_status] => down

[card] => PE2G2BPi35
[port] => 0
[slaveNIC] => igb3
[bypass] => closed
[firmware_version] => aa

[igb3] => stdClass Object
[media_status] => stdClass Object
[link_status] => down
[card] => PE2G2BPi35
[port] => 1
[is_slave] => yes
[bypass] => closed
[firmware_version] => aa
[version] => 3.0
[core_version] => 3.10.4

Note the port, slaveNIC and is_slave values. In this example with a 2-port bypass card, igb2 is the master, and igb3 the slave. When specifying an interface, you must specify the master port, not the slave. Bypass NICs operate in pairs, so if this was a quad-bypass card, we would have 2 pairs of bypass ports - igb2 with slave igb3, and igb4 with slave igb5.


Use the open command to force the bypass "open", which means not in bypass. When forced open, the watchdog timer (WDT) is stopped and a system software failure will not result in the system being bypassed. Note that a cold boot will reset the bypass to being "closed" (the default state), but a warm boot will not.

# bypass open

Open All Bypass Ports

# bypass igb0 open

Open the igb0/igb1 bypass ports.


The close command will enable the bypass state, where the bypass ports are connected as a passive coupler. Traffic will pass unrestricted between the ports, and the OS will see no link or activity on the bypass ports.

set_wdt tmo

The set_wdt command sets the watchdog timeout (WDT) on the card to tmo seconds. The TMO is the amount of time the WDT will keep the ports in the "open" state while waiting for a touch. Once the timer starts, if the WDT is not "touched" before the timer expires, the card will be returned to the bypass state.

Set the timeout to 10 seconds

# bypass set_wdt 10


Issuing a disablewdt command will turn off the WDT, preventing the bypass card from automatically changing states in response to a watchdog timeout.


touching the card will reset the WDT on the card, setting the timer back to the timeout. There's rarely a need to run a touch from the command line in normal operation touches are typically issued by the bypassd program to keep the bypass open.

# bypass touch

resets the watchdog timers on all installed cards.

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