We were experiencing problems with one of our Windows 7 client applications that maintains a windows file share connection to a local server and it seemed to require lengthy application restarts during night shift on a regular basis.
Upon checking out the System Event Log I saw the following events recurring:
3/24/2014 12:05
Intel(R) 82567LM-3 Gigabit Network Connection
Network link has been established at 100Mbps full duplex.
3/24/2014 12:05
Intel(R) 82567LM-3 Gigabit Network Connection
Network link has been disconnected.
3/24/2014 11:37
Intel(R) 82567LM-3 Gigabit Network Connection
Network link has been established at 10Mbps full duplex.
3/24/2014 11:37
Intel(R) 82567LM-3 Gigabit Network Connection
Network link has been disconnected.
3/24/2014 7:55
Intel(R) 82567LM-3 Gigabit Network Connection
Network link has been established at 100Mbps full duplex.
3/24/2014 7:55
Intel(R) 82567LM-3 Gigabit Network Connection
Network link has been disconnected.
…etc …etc
The NIC was disconnecting then toggling back and forth between 10Mbps and 100Mbps at random intervals of ~60+ minutes all day but most frequently occurred overnight when the system is seeing lighter usage.
(I'm documenting and answering this myself here because it was an elusive problem but I'd like to accept any specific answers that don't involve completely disabling the monitor power savings and aren't just a nebulous 'try updating the drivers'.)
I found a related thread on the intel communities forum https://communities.intel.com/thread/9913 which pointed the finger at an issue with the NIC power savings mode on these Intel(R) 82567LM-3 Gigabit cards. They recommended disabling SIPS in the driver advanced settings as the disconnect/reconnect process seemed to cause trouble with properly restoring network shares for many users.
Unfortunately, the current version of the driver installed on our client PC did not expose any SIPS-specific settings and a registry search did not find the keys associated with this setting. Adjusting the other available power-related settings didn't have any impact.
A user on the Intel forums indicated that the problem was related to the NIC power savings mode activated when the monitor enters sleep mode so our workaround was to modify the group policy for these 2 particular PCs to allow us to disable the monitor entering sleep mode:
We have gone from 20 connect/reconnect events per day down to 0 events in the past 3 days.
It is just the adapter logging the link state.
Go into device manager/network adapters.
Right click your Intel adapter and select properties.
Select the advanced tab then locate the entry that says "Log Link State Event" or something similar to that.
Change it to disabled.