Diagnostic Switch Simplifies Testing

Diagnostic Switches Simplifies TestingSkorpion Diagnostic Switches assist the user in troubleshooting Ethernet networks by allowing a network sniffer such as Wireshark® to attach to an unused port on the switch and observe all traffic on the network. Skorpion Diagnostic Switches retain all the features of an unmanaged switch but perform like a repeating hub where all received messages are flooded to all other ports. There are two 5-port diagnostic switches in the series which differ only by the highest data rate supported. The EISK5-100T/H supports 10/100 Mbps networks while the EISK5-GT/H can additionally support gigabit speed. The EISK8-GT/H supports up to eight ports at 10/100/1000 Mbps speeds.

One benefit of switched Ethernet technology is that the switch restricts directed messages to only those ports party to the communication. This improves overall network throughput by not burdening end stations with useless traffic. However, this feature makes protocol debugging difficult because a sniffer (protocol analyzer) tool attached to an unused port on the switch cannot observe any directed messages of interest. In the past, the solution was to change out the switching hub with a repeating hub but with the Skorpion Diagnostic Switch this is unnecessary.

The Skorpion Diagnostic Switch retains all the virtues of switched Ethernet technology such as variable data rates on individual segments, auto-negotiation, Auto-MDIX but with one exception-no address learning. All messages-directed, multicast, and broadcast-are flooded to all ports on the switch allowing a sniffer or protocol analyser tool such as Wireshark the ability to observe all traffic on the network. The Skorpion Diagnostic Switch can be permanently installed on an installation or replaced with a regular Skorpion switch once a system is commissioned. This device can also be useful when developing embedded Ethernet devices because you can connect the Skorpion Diagnostic Switch between two embedded Ethernet devices and view their messages using Wireshark®.

Setup an Easily Accessible Test Point

Instead of installing a managed switch with port-mirroring in each equipment room, install a diagnostic switch in each control panel that has an Ethernet connected BACnet Building Controller (B-BC). Just about all the traffic you would be interested in is going to be related to the building controller.

Insert the diagnostic switch between the building controller and the IP network. If the building controller is located at the end of a single Ethernet drop, the diagnostic switch will act as a three-port active tap with one connection to the building controller, one connection to the IP network and one connection reserved for a protocol tool such as Wireshark running on a laptop. In fact, with this setup you gain two additional spare ports. It is not necessary to leave the laptop connected. Just connect it when you need to. The diagnostic switch is active in the network at all times but will not reduce any communications throughput other than the normal latency of a store-and-forward Ethernet switch. Just plug in your laptop when you want to do protocol analysis, configure a device on-line or to observe web pages.

If the building controller is located mid-span of the IP network with a backbone connection coming into the control panel and exiting the control panel, use the diagnostic switch for all connections leaving two spare connections – one for the laptop and one additional spare. You can also use the spare port for connection to another control panel.

With either of these situations you will be able to observe all traffic from all ports but throughput could be impacted due to the flooding of traffic. However, with modest traffic you might not even notice the difference plus you gain the convenience of having a network diagnostic port ready at all times to be used.

The diagnostic switch simplifies testing and is priced the same as a standard five-port unmanaged switch, making it ideal for network troubleshooting.

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