Paul Jakma wrote: > On Wed, 17 Oct 2007, Garrett D'Amore wrote: > >> I think this is only true when the host operating system is not >> running. If the host OS is running, then gigabit should be fine. > > So what happens when the host OS stops running suddenly (crash or > hardware fault)?
The AMT firmware is supposed to figure this out. I think the NIC drops down to 100Mbps mode. I'm not sure exactly how this monitoring is done. I imagine there is a watchdog register that is tickled or somesuch. > > Further, it seems the host OS needs to re-enable the ARP intercept in > the NIC hardware on shutdown. I'm very curious if that means a sudden > host stop will render the AMT LOM inaccessible in short order.. No, AMT is precisely designed the way it is to deal with this case. If you crash your operating system, within a second or two (or thereabouts) AMT figures out that the host is out to lunch, and the ME takes over. In case anyone is curious, the ME/AMT environment is really like an embedded service processor, and as such, traffic to it is probably not terribly common. It has a serial port/console shunt, and also provides some other features like remote host reset capability, etc. -- Garrett
