We have had a rather odd issue arise in our network over the past few days. We had a Comcast modem (in bridge mode) that goes to a Cisco E1500 and multiple switches behined it (unmanaged simple 5 and 8 port switches).
A few days ago this started... computers would get an IP and all the information (ran an ipconfig /all) and open one or two web pages then go dead--cant resolve host nor open web page--then connectivity comes back--then drops out for good.
We upgraded to a DLink DIR-655 and a DLink 16 port switch. Still having the issue. The DLink router is in default configruation and no other servers/routers on the network.
Where to start with the troubleshooting? It is a network that was working fine until a coupe of days ago and nothing has changed--just a DHCP network with Windows PCs.
I have often seen devices that don't connect or won't pull IP address--but what would cause intermittent connectivity issues that will not go away.