Product Documentation

Connecting the Cables

Jul 08, 2013

When the appliance is securely mounted on the rack, you are ready to connect the cables. Ethernet cables are connected first. Connect the power cable last.

Danger: Before installing or repairing the appliance, remove all jewelry and other metal objects that might come in contact with power sources or wires. When you touch both a live power source or wire and ground, any metal objects can heat up rapidly and cause burns, set clothing on fire, or fuse the metal object to an exposed terminal.

Types of Ethernet Cabling

The appliance uses standard (copper) Gigabit Ethernet (GigE, also called 1000BaseT), which is backward-compatible with Fast Ethernet (100 Mbps) and standard Ethernet (10 Mbps). Repeater 8500 and 8800 appliances optionally have a gigabit fiber card. CloudBridge 4000/5000 supports 10 Gbps SFP/SFP+ interfaces.

Gigabit Ethernet Networks
Gigabit Ethernet is the minimum specification recommended for use with Repeater and CloudBridge products, because it offers higher performance and is easier to work with than Fast Ethernet. Gigabit Ethernet is indifferent to whether cables are straight-through or cross-over. For convenience, however, Citrix recommends that installations be wired as if they used Fast Ethernet, so that legacy Fast Ethernet equipment can easily be accommodated.

With Gigabit Ethernet, use only cables marked Category 5e or Category 6.

Fast Ethernet (100 Mbps) Networks
When the appliance is connected to a Fast Ethernet (100 Mbps, 100BaseT) device, the cabling rules for Fast Ethernet apply.

Fast Ethernet cabling issues and autonegotiation failures are the leading causes of installation problems. In addition, compression delivers higher performance if your LAN is running at gigabit speeds. Therefore, upgrading to Gigabit Ethernet when installing an appliance is a good practice.

Connector Polarity and Cross-Over Cables- Fast Ethernet has two connector polarities: computer and switch, comparable to DCE and DTE in RS-232. Connecting a computer to a switch requires a straight-through cable. Connecting a computer to a computer or a switch to a switch requires a cross-over cable (analogous to a null modem cable in RS-232). Routers generally, but not always, use the same connector polarity as computers.

Both Ethernet ports on the appliance are wired as computer ports. Therefore, for Fast Ethernet:
  • When connecting an appliance port to a switch, use a straight-through cable.
  • When connecting an appliance port to a computer or router, use a cross-over cable.

The uplink port on a switch can be thought of as having a built-in cross-over cable.

Fast Ethernet Auto-Negotiation Failures- The Fast Ethernet specification has a flaw that leads to autonegotiation failures when one end of a connection is set to Auto and the other is forced to 100 Mbps full-duplex. The Auto connection usually sets itself to 100 Mbps half-duplex. This mismatched connection functions at low network loads but behaves erratically under high loads. This problem is built into the Fast Ethernet standard and is not a bug in the appliance.

To avoid this problem, set the units on each end of the cable to the same mode, whether Auto or a specific mode, such as 1000 Mbps Full Duplex. Citrix appliances default to Auto. This setting can be changed through the management interface, on the Configuration: Network Adapters page.

In a fail-to-wire installation, the issue extends to both appliance ports plus the ports they connect to. All four ports should be set to Auto, or all four should be forced to the same mode.

The autonegotiation problem can occur anywhere along the path between LAN and WAN, not necessarily on the connection to the appliance itself. It is not unusual to discover long-standing cases of this problem in installations where past performance expectations have been low. It should be suspected when the appliance reports high packet losses. If the mismatch occurs on a link directly connected to the appliance, the Alerts page reports a half-duplex connection.

Older Fast Ethernet Equipment- Older Fast Ethernet products do not support full-duplex operation at all. Older equipment is often less reliable with autonegotiation as well.

10BaseT (10 Mbps) Ethernet
The appliance is compatible with 10 Mbps (10BaseT) Ethernet, but such equipment is generally half-duplex only. The maximum performance that can be supported on such a network is quite low. 10BaseT Ethernet should be avoided or replaced when possible.

Cabling is the same as with Fast Ethernet.

Installing the Ethernet Cables

Connect the Ethernet cable(s) to the ports marked apA or Accelerated Pair A in the figures below. The appliance uses Gigabit Ethernet ports that auto-configure for Gigabit, 100 Mbps, or 10 Mbps networks. These ports are located on an add-in card, and on some appliances these ports are labeled Accelerated LAN/WAN Ports.

Some appliances are shipped with more than one pair of accelerated LAN/WAN ports (Accelerated Pair A and Accelerated Pair B). On such appliances, assign the Management IP address to the subnet attached to Accelerated Pair A.

Figure 1. Appliance connectors


On an appliance equipped with an Ethernet bypass card, the motherboard Ethernet (Primary and Aux1) ports are not accelerated, and are shipped with plugs to prevent cables from being installed into them accidentally. If needed, you can use them for administrative purposes, or for a back channel for group mode or high availability mode. If your appliance does not have an Ethernet bypass card, the motherboard ports are an accelerated pair.

You can use either port of an accelerated pair as the WAN-facing port, but when you define your links, you must know which port that is. A good convention is to use apA.1 as the LAN port and apA.2 as the WAN port. If only one port is used (WCCP or virtual inline installations), use apA.1.

Figure 2. Ethernet port locations on the appliance


Basic Cabling for Inline Mode

The choice of straight-through or cross-over cables for inline mode depends on the type of unit attached to the appliance. Straight-through cables are used with switches. Crossover cables are used with routers and computers.
Note: Cabling errors are a major source of installation problems. Use straight-through or crossover cables only as indicated. The only exception is an installation where all devices connected to the appliance use Gigabit Ethernet, which automatically detects and compensates for the type of cable.
Figure 3. Basic cabling, inline mode


Troubleshooting Problems with Cabling (Inline Mode Only)

If your appliance has a bypass card, you can test the cabling for an inline installation as soon as the cables are connected, before powering on the appliance. Cabling for other modes can be tested only after the appliance is configured.

To test the cable connections of an appliance containing a bypass card, deployed in inline mode, verify that packets can be sent through the appliance, from the network connected to one side of the appliance to the network connected to the other side. You can use ping, ftp, or another convenient program. An appliance without a bypass card blocks traffic if not powered on, so skip this test for such an appliance.

Problems at this stage can have one of the following causes:
  • Simple cabling errors. Cables might be disconnected or plugged into the wrong port. Inspect your cabling set-up. Note that many appliances have two unused Ethernet ports. Make sure that you are using an accelerated pair.
  • 10/100 Ethernet. The use of a cross-over cable where a straight-through cable is needed, or vice versa. Compare your cabling to the diagrams in the cabling instructions.
  • 10/100 Ethernet. A cable connected to the Uplink port of a switch when it should connect to a regular port, or vice versa. Inspect your cabling set-up.
  • 10/100 Ethernet. If all else fails, replacing either of the cables with the opposite type of cable should work (that is, replace a straight-through cable with a crossover cable or vice versa).

Basic Cabling for High Availability Mode

The two appliances in the high availability pair are installed onto the same subnet in either a parallel arrangement or a one-arm arrangement, both of which are shown in the following figure. In a one-arm arrangement, use the apA.2 port (and, optionally, the apB.2 port), not the apA.1 port.
Figure 4. Cabling for High-Availability Pairs


Do not break the above topology with additional switches. Random switch arrangements are not supported. Each of the switches must be either a single, monolithic switch, a single logical switch, or part of the same chassis.

Figure 5. Ethernet port locations on the appliance


The spanning-tree protocol (STP) is not recommended on the router or switch ports attached to the Repeater appliances, because STP can increase the failover time by tens of seconds.

Basic Cabling for Virtual Inline and WCCP Installations

For a virtual inline or WCCP deployment, use a crossover cable to connect the router to apA.1 on each appliance. The apA.1 port is not marked on the appliance. Virtual inline installations are always connected directly to a router port, or when deployed in high availability pairs, to a switch that is connected directly to a router port. WCCP installations must be on an isolated subnet, but the isolation can be achieved through methods other than a dedicated router port, such as with a VLAN.
Figure 6. Basic cabling, virtual inline and WCCP modes


Figure 7. Basic cabling, virtual inline or WCCP high availability pair


Connecting the Power Cable

A CloudBridge 600 Series or Repeater 8500 series appliance has one power cable and Repeater 8800 series appliance has two power cables.

To connect the appliance to the power source
  1. Connect one end of the power cable to the power outlet on the back panel of the appliance.
  2. Connect the other end of the power cable to a standard 100V/240V power outlet.