Expert's answer

I have worked with appliances similar to this and learned a lesson early one - proceed carefully and slowly. I would suggest using Wireshark or your network analyzer of choice and look at the ports where the traffic comes into the device from your Internet connection and where to enters your network. Do this on both ports when the device is first connected to the network and then again when your network seems to come to a half. The first "sniffing" of network traffic will give you a baseline of the way things are working and will help you when you can no longer get anything to work on the network after several hours have passed. You should be able to get some idea as to where the problem is by seeing the traffic that is or isnt passing through the unit when you begin to see the problem you mentioned.

Review the documentation that shipped with the device to ensure that you have it connected to the right point in the network. I usually place devices like this just inside the firewall and the remainder of the network it is servicing. Look at the error logs in the unit to see if it gives you any indication of what is or isnt working when your network traffic goes awry. Make sure that you have the latest version of the firmware for the appliance installed. We have all run into our fair share of bugs when implementing either an appliance or other software service that might have been avoided if we had applied the latest firmware updates.

One option, if nothing else works and assuming that you have your configuration documented, is to do a factory reset of the appliance and rebuild your configuration one step at a time. It is entirely possible that one or more of the configuration changes you made might either be fighting between themselves or be the cause of the problem. If you do have your changes documented, you might be able to resolve the problem you are running into by carefully backing out the changes in the reverse order they were made (i.e. the last one made is removed first, then the next previous change is removed, etc).

If you still haven't been able to find the source of the problem, make use of the support contract that I hope you have. If you don't have one, see if you can purchase a one-time support call or you may need to consider biting the bullet and getting the contract. While support contracts can be pricey, like the Mastercard commercial, they can be priceless when you really need them and havent been able to resolve the problem through other means.

In checking the specs of the unit you mentioned, it appears capable of handling 5,000 users. While you didnt mention the number of users on your network, I will assume that you aren't near this limit. Another item to check is the speed of the Internet connection that you are using. The specs indicate it supports a connection speed of up to 20 Megabytes. If you rspeed is close to this or you have some heavy users, or a combination of the two, it is possible that the device simply can't keep up with the combination. This is where talking to the technical support folks at Cymphonix might yield some configuration changes that could improve the situation or give you the news that an upgrade to the next higher model might be necessary.