A‑Link and Private Networks

Every everRun system requires one private network, referred to as priv0, that connects the two everRun physical machines (PMs). The private network is used only for discovery and can have no other entities on it that respond to IPv4 broadcasts.

In addition to the private network, an everRun system has A-Link networks to increase data-replication performance between PMs. A-Link networks let you sync disks, shunt networks, migrate, perform heartbeat checks, and sync fault-tolerant memory.

By default, the private network also performs the role of an A-Link network under the following conditions:

• If the private network speed is at least 10 Gb
• If the private network speed is less than 10 Gb and the system contains no other 10 Gb ports (other than the management link). In this situation, you can remove the A-link role later as long as the private network is not currently in use as an A-Link and is not the only remaining A-Link.

The private network cannot perform the A-Link role if its speed is less than 10 Gb and the system contains any 10 Gb ports (other than the management link). However, you can assign the A-Link role to the private network at a later time.

The simplest private network consists of a single Ethernet cable (crossover or straight-through) that directly connects an embedded Ethernet port on each server. If a networking device other than a single Ethernet cable is used for priv0, see SplitSite Configurations.

Connect A-link networks between PMs either directly (that is, in the same manner that you connect the private network) or through a network switch.

Be sure to set up redundant A-Link networks.

The everRun installation software sets up the private network. It also sets up A-Link networks for any A-Link network ports that are physically connected at the time of the installation. To set up an A-Link network after the installation is complete (recommended if the network includes many additional A-Link network ports), see Connecting Additional Networks.

Related Topics

Business and Management Networks

A‑Link and Private Network Requirements

Network Architecture Overview

Fixing a Network Connection