Sorry, I don't have a solution except to set both sides to auto, which you have observed will work. Setting one side to auto and the other side of the link to a forced setting is not a supported option, so even though the observations are interesting, that configuration is not valid. Also, duplex is not auto-negotiatied, which is why you get strange results when the two link partners are not configured identically.
On the other hand, forcing both sides to 100 Mbps Full duplex is a valid configuration and should work.Except for setting both sides to auto, I don't have a logical explanation or solution. Since the network connections are built in, make sure that you watch for BIOS updates that could affect the network connection and watch for future updates to your driver.
Also keep a close eye on the other conversations for similar problems and possible solutions. I have not been able to keep a close watch on the conversations recently, so I might miss something.
I wish I could offer you a better solution or explanation, but this is the best I can come up with right now. If I come across anything, I will post it.
Thanks Mark for your reply. We'll watch out for any further BIOS or driver updates.
Meanwhile, we'll also investigate migrating from our current forced 100 Mbps/Full on the PC and the switch to setting both sides to Auto-Auto.
I was wondering if you are aware of any script or tool that will allow us to change the NIC's speed without having to go through the properties of each PC. That would be helpful if we decide to switch to Auto-Auto.
Sorry I did not reply to your question. I completely missed this. In case anyone is wondering about the script question, you could use our save and restore VBS script for setting changes. At least this should work for like configurations.
If you have Intel(R) PROSet installed on your computers, then the script described at http://www.intel.com/support/network/sb/CS-028693.htm is already present. You could create the text file output from one of the computers and then use the script to "restore" the same configuration to each of the other adapters. This would configure all settings on all computers identically and would not be limited to the speed and duplex setting.
You could also use the prosetcl.exe utility (see http://www.intel.com/support/network/sb/CS-006259.htm) to configure only the speed and duplex setting. You can see a step through of the command line settings using prosetcl to configure speed and duplex at http://communities.intel.com/message/86858#86858. However, using this utility inside a script would require a more complicated script to enumerate the adapters and capture the index value of the adapter that needs to have the configuration changed. Using the VBS script would be simpler.
You can also use WMI to script configuration of adapters. See http://downloadcenter.intel.com/Detail_Desc.aspx?agr=Y&DwnldID=9405&lang=eng for the documentation. However, if you're not used to using WMI, this might be the most complicated solution.
Note that when you run any script or configuration utility, the "user" running the script will need to have administrator level permissions on the machine or the configuration changes will fail.
where XXXX is the key number (ie 0008) that pertains to the 82579LM adapter (do a search of the keys)
find the subkey “LinkNegotiationProcess”. If the subkey is present, change the value to 2.
If subkey is not present, create it, add a string value and set it to 2
Exit regedit, reboot the system.
One of the engineers at Intel put together this utility to allow you to change the registry setting. Feel free to download it and give it a try. You should consider this utility to be beta quality since we have not put it through all the normal validation tests, but as far as we know, the utility has no bugs.
This utility has helped some people who have reported an issue where the speed and duplex negotiation gives unexpected results with some switches. By default, the 82579 connections always auto negotiate when you choose one of the "fixed" speed and duplex settings. The default behavior reduces the options advertised during speed and duplex negotiation. Using auto negotiation without advertising other speeds seems to work best with most link partners, but some switches need the FORCED mode that you can set with this utility. This utility will not help resolve other connection issues.
The instructions and download can be found at
After you use the utility to update the Windows registry, you must restart the adapter. You can restart Windows or use Windows Device Manager to disable and enable the network connection.
Also, we would love to hear back from you if this utility helped you or did not help you connect at the proper speed and duplex.
I know that some of you have been affected by the duplex mismatch issue with the Intel 82579 Network Connections, so I wanted to let you in on what is going on. You can find bits and pieces of this information in other replies throughout the community, but I wanted to put everything I know ion the issue nto one post.
Let me start by making it clear how the driver (e1c) for the Intel 82579 Network Connections behaves when you configure one of the non-default speed and duplex options. The driver uses "selective advertisement" to negotiate a speed and duplex setting. For example, if you configure the network connection for 100 Mb, full-duplex mode, then that is the capability advertised to the link partner. This method works fine in most cases and usually avoids mismatches that can occur when two sides of a connection are forced to different settings. Unfortunately, as some of you have reported in this community, this method does not always work. Why not? Here is one case we have determined where "selective advertisement" does not work.
Intel has determined that the Intel 82579 Network Connection may not establish link properly to certain Cisco line cards that feature Cisco proprietary pre-standard Power over Ethernet (PoE) and have that feature enabled. The pre-standard PoE feature generates pulses on the cable that can be mistaken by the 82579 as an FLP advertising a 100Mb half-duplex mode auto-negotiation offer. If the Intel 82579 Network Connection is configured for 100 Mb full duplex, it will still start by attempting to auto-negotiate. If it mistakes the PoE pulse as a 100 Mb half-duplex offer, it will accept that offer and configure the interface for half-duplex, resulting in a duplex mismatch between the link partners. This, in turn, will result in extremely poor performance or a loss of communication.
If you are experiencing the duplex mismatch issue where you are trying to force 100 Mb, you have a few choices to work around the issue.
1. You could configure both sides for the default auto negotiation options.
2. You could disable Power over Ethernet on the switch port.
3. You could make a Windows registry change manually, by a script, or using a utility. This registry key change has been reported by several people to fix the issue.
Here is the registry key information in case you want to do this manually or need the values for your own tools or scripts.
• Registry Key: [REG_SZ] “LinkNegotiationProcess”, with the following values:
• ‘1’ (Auto-negotiate link). This is the default value.
• ‘2’ (Force link speed for 10/100 Mbps link speeds). This is the value you will use as a workaround for the duplex mismatch issue.
The utility that you can use to make the registry change is available at:
I hope this information is helpful. I will let you know if I get more information.
Good to see problem of many users getting solved. Not in my case. The download seems to be targeted to windows 7 PCs.
What if the operating system is Windows XP?
I tried all the options but none working out for me. Switches are fully managed L2, 10/100mb ethernet and PCs having gigabit adapters. Problem with motherboard having intel 82566DC Controller. Motherboard being intel Q963 chipset
You might want to take a look at this thread:
I am not sure what your issue is, but the older driver found in the other thread might help.
The discussion in this thread is for a completely different hardware and driver, so the suggestions you try from this thread might not apply.