WeOS
5.20.1

# Fastlink

In this section you will learn:

- What the “fastlink” setting does
- On what ports the “fastlink” setting applies

## Purpose of “fastlink” on Gigabit Ethernet copper ports

Gigabit Ethernet copper ports typically have longer “link down” detection time than Fast Ethernet copper ports. The reason is that according to the Gigabit Ethernet standard, a port operating at gigabit speed and experiencing a link loss, will try to negotiate 100 Mbit/s speed before determining the link as down.

This property of the Gigabit Ethernet standard limits how fast layer 2 redundancy protocols can react on link-down events, thus failover times will typically increase by around 300-400 ms.

By setting the “fastlink” property on a gigabit copper port, the port will determine the link as down without trying to negotiate the link to run at 100 Mbit/s.

## Ports applicable for “fastlink”

This setting only applies to Gigabit copper ports, given that the underlying hardware has support to circumvent the 100 Mbit/s negotiation.

- The Dagger hardware (1548P PHYs) supports “fastlink”.
- The setting does not apply to Fiber SFP ports, as there is no speed negotiation for fiber.
- The setting does not apply to 100 Mbit/s Ethernet copper ports, as the property causing link detection delay is specific to Gigabit