Product Documentation

Common Hardware Components

Jul 08, 2013

Each platform in the CloudBridge family has front panel and back panel hardware components. The front panel has an LCD display. The number, type, and location of ports vary by hardware platform. The back panel provides access to the fan, power cable, serial console cable, and Ethernet ports.

LCD Display

When you first install the appliance, you can configure the initial settings by using the LCD keypad on the front panel of the appliance. The keypad interacts with the LCD display module, which is also on the front panel of these appliances. When you have installed the appliance and are ready for initial configuration, use the LCD display and keypad to set the IP Address, subnet mask, and default gateway. You can then connect to the appliance's IP address to access the main user interface.

To use the LCD keypad to perform basic configuration, see Setting Initial ParametersSetting Initial Parameters.

Ethernet Ports

A typical appliance has four Ethernet ports: two bridged ports and two motherboard ports. The bridged ports provide acceleration. Typically, the bridged ports are on an Ethernet bypass card, which activates a fail-to-wire (FTW) relay if a failure occurs, so that data transmission continues. In this case, the motherboard ports can be used for secondary purposes. On an appliance that does not have an Ethernet bypass card, the two motherboard ports are bridged. In either case, the two bridged ports form an accelerated pair. Acceleration is supported only on accelerated pairs.

On an appliance with a bypass card providing two bridged ports, the bridged ports are called Accelerated Pair A (apA), and the two motherboard ports are called Primary and Aux1. In this case, the motherboard ports can be used for the user interface and for the back-channel access required for group mode or high availability mode.

Every appliance has an Accelerated Pair A. Some appliances have a second accelerated pair, called Accelerated Pair B (apB).

The ports are named as follows:
Table 1. Ethernet port names
Motherboard port 1 Primary (or apA.1 if no bypass card is present)
Motherboard port 2 Auxiliary1 or Aux1 (or apA.2 if no bypass card is present)
Bridge #1 Accelerated Pair A (apA, with ports apA.1 and apA.2)
Bridge #2 Accelerated Pair B (apB, with ports apB.1 and apB.2)
Bridged Ports
In inline mode, the pair of bridged ports acts as a transparent bridge, as if it were an Ethernet switch. Packets flow in one port and out the other. The bridges can also act in single-ended mode (WCCP or virtual inline), in which packets flow in one port and back out the same port.

A bypass card is standard equipment on some models and optional on others. If the appliance loses power or fails in some other way, an internal relay closes and the two bridged ports are connected electrically. This maintains network continuity but makes the bridge ports inaccessible.

Motherboard Ports
While the Ethernet ports on a bypass card are inaccessible when the bypass relay is closed, the motherboard ports remain active. You can sometimes access a failed appliance from the motherboard ports when the bridged ports are inaccessible.
Port Parameters
Each bridge and motherboard port can be:
  • Enabled or disabled
  • Assigned an IP address and netmask
  • Assigned a default gateway
  • Assigned to a VLAN
  • Set to 1000 Mbps, 100 Mbps, or 10 Mbps at full or half duplex

After the appliance is installed, all of these parameters except the speed/duplex setting can be set on the Configure Settings: IP Address page. The speed/duplex settings are set on the Configure Settings: Interface page.

Notes about parameters:
  • Disabled ports do not respond to any traffic.
  • To secure the user interface on ports with IP addresses, select HTTPS instead of HTTP on the “UI” page.
  • Inline mode works even if a bridge has no IP address; all other modes require that an IP address be assigned to the port.
  • Traffic is not routed between interfaces. For example, a connection on bridge apA does not cross over to the Primary or Aux1 ports, but remains on bridge apA. The entire issue of routing is left to your routers.
The Primary Port
If the primary port is enabled and has an IP address assigned to it, the appliance takes its identity from it. That is, user-interface (UI) displays on other units use this IP address to represent the appliance. If the primary port is not enabled, the IP address of Accelerated Pair A is used.
The primary port is used for:
  • Administration by using the Web-based UI
  • A back channel for group mode
  • A back channel for high availability mode
The Aux1 Port
The Aux1 port is identical to the primary port. If the Aux1 port is enabled and the Primary port is not, the appliance takes its identity from the Aux1 port’s IP address. If both are enabled, the Primary port's IP address is the appliance's identity.
Using Multiple Bridges
Some appliances have two or even three pairs of bridged ports, referred to as Accelerated Pair A (apA) and Accelerated Pair B (apB). The two bridges can be used to accelerate two different links. These links can either be fully independent or they can be redundant links, connecting to the same site. Redundant links can be either load balanced or main link/failover link pairs.

To handle load balanced links, the bridges use the following algorithm: when it is time to send a packet for a given connection, it is sent on a bridge that received the most recent input packet. The appliance honors the link decisions made by the router, and automatically tracks the load balancing or main-link/failover-link algorithm in real time. For non-load balanced links, this algorithm ensures that packets always use the correct bridge.

WCCP and Virtual Inline Modes. Multiple bridges are supported with both WCCP and virtual inline modes (not shown). Usage is the same as the single-bridge case, except that WCCP has the additional limitation that all traffic for a given WCCP service group must arrive on the same bridge.

High Availability with Multiple Bridges. Two units with multiple bridges can be used in a high availability pair. Simply match up the bridges so that all links pass through both appliances.