Last night I was implementing Diffserv 46 QoS on my Cisco 2821 that has an HWIC-1GE-SFP card and a GLC-ZX-SM fiber module. When we inserted the commands, and applied the service policy to the interface, we immediately dropped network connectivity. The interface went in to an up/down state and would not come back. We went as far as removing the commands and rebooting the router. We have been told that the GLC-ZX-SM module failed. Does anyone know what could cause this?
I have this problem too.