Cyclades AlterPath OnBoard, Administrator'S Manual

Page: 77 / 460

Introduction 41
Understanding Ethernet Ports on the OnBoard
Understanding Ethernet Ports on the OnBoard
The OnBoard’s two public Ethernet ports are used for connecting to the public
(or management) network. The managed private side of the OnBoard (which
is made up of 24 or 40 private Ethernet ports) is isolated from the public side
to ensure security. Access to all connected servers is consolidated through the
one publicly known IP address.
Private Ethernet Ports
The OnBoard is aware of only a single interface to the private network: priv0.
for communicating with the connected devices. priv0 sends packets to and
receives packets from the 24 or 40 private Ethernet ports.
Private Ethernet ports on the OnBoard are connected to the service
processors’ or other device’s dedicated Ethernet ports.
Each private Ethernet port may be connected to multiple service processors,
for example through a blade manager that has multiple service processors, and
in those cases a single private Ethernet port may require multiple IP addresses.
All communication among private Ethernet ports are blocked unless priv0 is
the sending or receiving port.
Public Ethernet Ports
On the public side of the OnBoard, the primary and secondary Ethernet ports
are referred to as
eth0
and
eth1
. Optionally-added Ethernet PCMCIA cards
are referred to as
eth2
and
eth3,
and if they are present, they are treated as
public interfaces.
The secondary Ethernet port on the OnBoard can optionally be configured for
failover, which is also referred to as bonding. Failover is important for high-
availability environments where constant accessibility is required to support
mission-critical applications. Failover automatically redirects traffic from the
primary Ethernet port to the secondary Ethernet port if the primary interface
fails. The primary Ethernet port continues to be monitored, and when it starts
functioning again, traffic is then automatically redirected back through the
primary Ethernet port again. All connection sessions continue without
interruption.
With failover, both the primary and secondary Ethernet ports are assigned a
single IP and single MAC [Ethernet] address.