Category Archives: Lync

Lync DHCP options and Windows 2012 R2

Lync2013Recently had a issue where Lync phones (Polycom CX600) using number and pin where unable to download the CA certificate chain. Tethered phones worked fine. Some network packet inspection revealed that the DHCP server did not provide any of the options 43 information. The client (phone) asked for the correct vendor class “MS-UC-Client”, but there was no response from DHCP server. To add these options to the DHCP server we used the same script as we always use, so it was sure there was nothing wrong with the server. Asked the crew running the network equipment to check but they did not notice anything being blocked.  Continue reading Lync DHCP options and Windows 2012 R2

Lync server 2010 rtchost.exe crashes after Windows Update.

Lync2013 After running Windows update on a Lync 2010 edge server I was unable to communicate with external contacts. I could see their presence but no chat/video or audio. The eventlog contained lots of event 1001 “Information”(Why not error !!!!!) that RTCHOST.EXE crashed. Probably failed installation of KB2982385.

Continue reading Lync server 2010 rtchost.exe crashes after Windows Update.

Provisioning Lync federation with Skype.

Lync2013If you want your Lync users to be able to federate with Microsoft and Skype you will need to go to and request a new service. Login with the live account that has permissions to access your Microsoft Licenses through the Microsoft licensing portal.

Enter your Licensing type and  License Agreement number.

Add you Lync Edge serve Access name ( and all domains that are handled by this edge server ( …

Wait for the emails from LCSprovisioningsupport, one when your request are entered and one when provisioning has been completed. Usually no more than 2-3 hours.

Also remember to enable federation with messenger/skype in the Lync Control Panel og Lync Management Shell.

Outlook contact phone number will not display in Lync client.

Lync2013There have been some issues where phone numbers in Outlook does not show in Lync 2013 Client. After some time we discovered that this was because of a Lync/Office update.  Yesterday Microsoft releast August update for Lync 2013 Client, this includes a fix for this issue. The updated version is 15.0.4641.1000

Can be downloaded from :

Disable missed call notification in Lync

If you have Lync enterprise enabled, and use simultaneous ringing on Lync and mobile, you are probably tired of all the Missed Call Notifications in your  inbox. I have disabled this in the Lync Client policy

Set-CsClientPolicy -Identity “PolicyName” -EnableCallLogAutoArchiving $False

You will still get your IM conversations saved in Outlook.

Lync server 2013:Automatic collection of configuration data failed.

Wanted to install a second Central site in my Lync 2013 deployment. Added the site , pool and servers to my Topology Builder. Deployed it and started installing the new server. When installation came to the point where it is supposed to locate CMS and replicate it : “Automatic collection of configuration data failed” . What now?

Continue reading Lync server 2013:Automatic collection of configuration data failed.

msRTCSIP-GroupingID editor.

This is my msRTCSIP-GroupingID editor. I use it to segregate addresslists in Lync solutions. It takes a commaseparated text file containing Company name and GUID for the addresslist assigned to this Company (filename : groupingids.txt) sample:


I have placed this file on the Lync share for my own convenience. Powershell script Groupingeditor.ps1 loads these values to a listbox. It let you search for users and then apply the groupingID to the selected users.

Next Version will contain possibillities to select entire OU’s and list users containing a spesific GroupingID.


groupingids.txt (153B)

groupingeditor.ps1 (4.7KB)

Segregating addresslists in Lync

To segregate companies in Lync we would use the msRTCSIP-GroupingID attribute on the user Object.

Default value for this attibute is “<not set>”


This would as expected result in the default addresslist 00000…….


If we add a value to the attribute i.e : 00 11 22 33 44 55 66 77 88 99 AA BB CC DD EE FF



After adding this new value I would normally run :> update-csaddresslist

We now get a new a addresslist based on the msRTCSIP-GroupingID value.


This will be the addresslist users searches from Lync.


Lync client will not show contact photos when external.

Installed Lync 2013 on a Windows 2012R2 server. When I login with an external Lync Client there are no photos of internal users. A validation shows that the thumbnailPhoto attribute has bin populated with images of the correct size.

If the client Connect directly to the frontend server photos are presented correctly.

An examination of the Lync Addressbook shows the addressbook files and also the photo files. The photo files are renamed jpg files exported from Active Directory. The Lync server create these PHOTO files when a client request photos of users. Since these photos are placed in the addressbook folder they are downloaded through https to the Lync Client.

Running netstat on Lync front end did not show any TCP Connection from reverseproxy server !

A network monitor show that connection are reset after half a TLS 1.2 handshake – a strong indication that there is something wrong with ssl/tls. Revalidated all sertificates and also publishing rules on F5 reverseproxy.

Used Bing to find any issues regarding TLS 1.2 and Windows 2012 R2, and yes, someone have hade the same issue. Entered registry keys as below – rebooted and now it works –

To Resolve this issue do the following:

– On the Lync 2013 server open the registry and browse to the following location: HKLM\System\CurrentControlSet\Control\SecurityProviders\SChannel\Protocols

– Create the following Key under Protocol: TLS 1.2

– Create the following two Keys under TLS 1.2: Client and Server

– Create the following DWORDs under both the Client and Server Key: DisabledByDefault and Enabled

– Under both Client and Server set the following: DisabledByDefault=1 and Enabled =0

– Reboot the server.

Entering these keys Disables TLS 1.2 on the server forcing the client and server to communicate over TLS 1.1.

Good Luck,


How to test network routing from remote Lync client.

Often we have to troubleshoot routing and firewall rules as seen from a client on a internal client subnets. I use PSEXEC and PORTQRY from Microsoft. This will work if it is a Windows pc and I have permissions to connect to it. Run these commands from a server in the server lan

I try to check if the port is open from the client to server ( :

\\clientpc.domain.local -c portqry.exe
-n -P TCP -e 443

If this fails I will run a tracert from the client to the server IP (

\\clientpc.domain.local tracert -h 8 -d