Basic Ethernet Troubleshooting Guide

This is a basic Ethernet troubleshooting guide. Before proceeding, you should try to eliminate any potential problems with your own network. Please see our Basic Connectivity Troubleshooting guide for more information on this.

Ethernet circuits provided by activereach Ltd are commonly used to connect a premise to the Internet. They can also be used to provide a site-to-site connection.

The termination of the circuit is always the same though, once the circuit has been installed (typically by BT Wholesale) to the premises – the circuit provider (which could be any BT reseller) will install their terminating device and the end customer can then connect their Ethernet based network.

Often this will be done using a router or firewall, and in many cases – both.

Ethernet based network diagram


Ethernet circuits are either 10Mbps or 100Mbps or 1Gbs. Larger sized circuits can be configured at a lower speed, but with the option of a seamless, hassle free upgrade if required at a future date.

If you are having issues with your Ethernet circuit, the following information may assist you in resolving the problem.

No Connectivity

It is important to find out where your connectivity has stopped if you are unable to access the Internet.

Do you have connectivity to your local switch?

Do you have connectivity to your local firewall?

Do you have connectivity to your local router?

Also ask yourself, has this worked before? And has anything been changed since it was last working? Have any devices on the network been restarted prior to the problem? How many devices on the network are having issues?

You will need to know some key information about your network to begin troubleshooting – such as the IP address of your firewall and router. Sometimes it is possible to gather this information from your local machine – but this may not always be the case.

Verify your local network connectivity on a Windows based machine by looking at the network status icon by the clock. If the network status icon has a cross through it, that may indicate an issue to your local switch which could be caused by the machine, cable, or switch port.

Open a command prompt by going to Windows Search and typing command. Run the command utility. This will present you with a black window. Type ‘ipconfig’ into the command prompt and press Enter.

Ethernet command prompt screen


In the text output, look for the IP addresses stated next to Local Area Connection IP Address and Default Gateway. If there is information shown here, you can attempt to send some data to the default gateway address (this is likely to be your firewall or router).

To do this, type ‘ping’ followed by a space, and then the IP address of the default gateway. Press Return.

Ethernet command prompt screen


If you see a series of ‘Replies’, then it suggests connectivity within your local network is okay.

To test connectivity to the Internet, try typing ping

Ethernet command prompt screen


Again, a series of ‘Replies’ indicates there is no issue getting traffic out to the Internet.

Slow Speed Issues

If you do not believe you are getting the speed you should be getting on your circuit, there are a few tests you can run to determine where the issue is.

Firstly, run a speed test from a couple of different speed test websites if you have not already done so.

The most likely cause for slow speeds is something else within your network is using up your available bandwidth – make sure you investigate the most probable causes. Even mobile phones and tablets can use vast amounts of bandwidth, especially if they are making use of automated cloud based backup services.

If it is not possible to investigate thoroughly, the next best thing to do is isolate your entire network by disconnecting it from the Internet. Normally this can be done by disconnecting your switch from your firewall (depending on your setup). This will obviously cause major disruption, so do not do this without good planning. Once this has been done, you can connect a single machine to the exit point of your network (probably the firewall) and test the speed again.

If you are certain the speed issues are something you cannot isolate on your network, and they are caused by your activereach managed circuit or equipment – we will be happy to investigate the matter once you have raised a case with us.

This is just a starting point in the main troubleshooting of issues on your network and connection – there are many technical issues that can occur and it is nigh impossible to create a guide that covers every eventuality.

Carrying out the steps detailed here will greatly assist us in helping resolve your problem should you need to raise a case with us for further investigation.

activereach can help you with a network security audit as well as a full range of UK business broadband and Internet access circuits. Give us a call on 0845 625 9025 or contact us to find out more.