Tuesday 3 January 2012

Slow Network Speeds with SBS 2008 and 2011: NIC Binding Order

Most server boxes today come with at least 2 NICs. In some cases they come with four or more! As a result we need to pay particular attention to how the networking structures are set up in the OS.
The following is a Snip of a production SBS 2008 server:
To get the Advanced Settings screen:
  1. Start –> NCPA.CPL [Enter]
  2. Hit the ALT key if the File menu is not seen.
  3. Click Advanced.
  4. Click Advanced Settings.
Note the order that the NIC bindings are shown in.
In this case, Local Area Connection 2 is the NIC that was not plugged in during the OS setup phase. Yet, the OS somehow managed to place that NIC at the top of the binding order.
What does that mean?
Network services run slower as the OS will poll the disabled NIC _first_ before the NIC that the services are actually connected to.
So, for any network that is experiencing any kind of slowness the following should be done in the troubleshooting process before touching any of the NIC driver settings or OS internal configuration:
  1. Check the Switch!
    • Gigabit on _all_ ports please.
    • Make sure that switches with a higher port density have the internal backbone to handle all or most ports running at full duplex Gigabit.
  2. Change the patch cable between the server and the switch.
    • Please.
  3. Verify the binding order on the NICs.
    • If a change is needed note that the server would need to be rebooted!
    • In the case above:
      1. Move Local Area Connection 2 to the bottom of the list.
      2. Uncheck File and Printer Sharing on Local Area Connection 2.
      3. Uncheck Client for Microsoft Networks Local Area Connection 2.
  4. Check the Provider Order tab
    • image
    • Place the Microsoft Windows Network at the top of the list since it is definitely the most accessed part of the server’s networking.
We helped out a fellow consultant that was working with a client that had a really slow ACCPACC problem. Reports were taking _a long time_ to run. After running through a series of tests we checked the binding order and sure enough the NICs were way out of order.
After a reboot things took a day or so to straighten out. But once they settled down the reports were running in a fraction of the time it took before the change.
UPDATE: Thanks to Michael’s pointer in the comments. The order change was missing the “2”!
Philip Elder
Microsoft Small Business Specialists
Co-Author: SBS 2008 Blueprint Book
*Our original iMac was stolen (previous blog post). We now have a new MacBook Pro courtesy of Vlad Mazek, owner of OWN.


Michael Pope said...


Great post - one of the things we check on every computer we touch.

Since you said that "Local Area Connection 2 is the NIC that was not plugged in during the OS setup phase," then shouldn't it be Local Area Connection *2* that is mentioned in steps 3.1, 3.2, and 3.3? It seems it's the one not being used, not Local Area Connection.


bttr said...

How about merging this information to http://social.technet.microsoft.com/wiki/contents/articles/small-business-server-2011-standard-build-document.aspx ?

Philip Elder Cluster MVP said...


My eyes were crossed. Fixed thank you.


It is almost impossible to merge the two. I will place a few more references within the build document to our Guide but it would be a bear to manage our guide on two separate sites where one is being edited by others (the wiki).



Doug H. said...


This is a great tip! On the SBS 2011 server I maintain this was indeed reversed.


Anonymous said...


Just an FYI, its update not "UPATE".

Enjoy your day


Philip Elder Cluster MVP said...

Meh, eyes were crossed and t was knotted. :D

Thanks for pointing that one out.