TTC Shelbyville – Technical Blog

It's not where you are at today, it is where you are going tomorrow. ~Steve Mallard

Archive for November 30th, 2009

Slow SQL Connection or Network in Windows 7 – Update

with 10 comments

Finally found a small problem with Windows 7.  After upgrading, we have discovered that Windows 7 was responding slow to our SQL Server 2005.  What we discovered is below.

Slow response times in Windows 7 to a SQL Server can be due to the LLMNR protocol.  This may be resolved by turning off the LLMNR protocol.

LLMNR is a protocol that allows both IPv6/4 computers to perform name resolution for the NetBIOS names of other computers without requiring a DNS server.

IPv4 hosts can use NetBIOS over TCP/IP (NetBT) to resolve computer names to IPv4 addresses for neighboring computers by broadcasting a NetBIOS Query.

All IPv4-based LLMNR hosts listen on the IPv4 multicast address 224.0.0.252 instruct their Ethernet network adapters to listen for Ethernet frames with a destination multicast address.

Windows Vista and 7-based LLMNR computers do not send or respond to unicast queries.

To disable LLMNR:

Modify Group Policy – Go to Search – Type GPEdit.msc – Enter – Navigate to the following and make sure Enabled is checked -


Computer Configuration\Administrative Templates\Network\DNS Client
\Turn off Multicast Name Resolution = Enabled

How does Multicasting Work?  Here’s a good explanation

Update -

LLMNR

Windows Vista and Windows Server “Longhorn” support Link-Local Multicast Name Resolution (LLMNR), which allows IPv6 hosts on a single subnet without a DNS server to resolve each other’s names. This capability is useful for single-subnet home networks and ad hoc wireless networks. Rather than unicasting a DNS query to a DNS server, LLMNR nodes send their DNS queries to a multicast address on which all the LLMNR-capable nodes of the subnet are listening. The owner of the queried name sends a unicast response. IPv4 nodes can also use LLMNR to perform local subnet name resolution without having to rely on NetBIOS over TCP/IP broadcasts.

Dawn M. Babian, GSAE
Instructor

Disabling LLMNR (Below)

Professional or Enterprise (Gpedit.msc)

Home Edition

Create a registry key as follows -

You also should go to your network adapter properties and disable all of the settings under the advanced properties such as TCP/Offload and other advanced settings.  Remember, not all adapters have advanced options – disable any settings that allow you to do so….

Written by TTC Shelbyville IT Department

Monday, November 30, 2009 7:12 pm at 7:12 pm

Performance Report in Windows 7

leave a comment »

Dawn Babian, Instructor gives this shortcut for your performance monitor.  At the search line, type: perfmon /report and hit enter.

Written by TTC Shelbyville IT Department

Monday, November 30, 2009 10:35 am at 10:35 am

Posted in Computers

Tagged with , , ,

Follow

Get every new post delivered to your Inbox.

Join 92 other followers