One of our long standing internet customers is the Chaplaincy at Edinburgh University. Their premises cover 3 x floors over 2 x adjacent buildings.
We received a call to report that their internet connection was dropping regularly and could only be restored by switching their router off then on again.
The network at the Chaplaincy is based on a Netgear DG834G
modem/router connected to a Netgear JFS51616 x port data switch that provides connections to individual outlets throughout the premises over a Cat 5 cabling system.
I first went to their comms room and checked the router and upgraded its firmware. With my laptop plugged directly into the router and the data network switch disconnected I couldn’t find anything wrong, the connection was steady and as fast as could be expected.
I then talked to the Bursar and asked about the devices that are connected to the network. I discovered that in addition to about 5 x PCs directly patched to the Cat 5 outlets there are several Apple Macs connected wirelessly through 3 x Apple Time Capsulesand 1 x Apple AirPort Expresswireless extension device.
The Time Capsules and MACs had been introduced after the original network had been configured. The Time Capsules are connected directly to the Cat 5 outlets. The Airport Express is connected wirlessly to one of the Time Capsules.
I soon discovered that the Time Capsules were set in their default DHCP mode and were issuing IP addresses to their connected Apple MACs which were in the same subnet range as those issued by the other Time Capsules and the DG834G router.
I knew that this would be the most likely cause of the network lock-ups and would explain why things would start working when devices were switched off then on. The Chaplaincy’s network configuration would certainly cause multiple devices to have the same IP address and result in a conflict that would in turn cause the network to freeze.
When deploying Time Capsules (and similar devices) in an existing network it is essential that they are set to Bridge Mode rather than DHCP mode. In Bridge Mode the connected MACs would obtain their IP addresses from the router (ie the DG834G) which would ensure that duplicate IP addresses are not allocated to devices connected to the network either directly or indirectly.
I made the required changes to the Time Capsules and as a result the Netgear DG834G now has total control over managing the IP addresses and there is no possibility of an attached device having the same IP address as another attached device (unless one of them is using an incorrectly assigned fixed IP address).
This has resolved the problems with no reported internet access problems for several months.
This situation highlights the fact that the natural assumption of most customers when they have an internet connection problem is that the problem must be with their internet service. It is our experience that most problems are associated with customer equipment or their local network settings.
Please get in touch using the Contact Form if you require assistance with internet connectivity problems.
………………………………………………………………………………………………………………………………………………………..
Comments are closed.