Skip navigation

Troubleshooting Microsoft Lync error with Airport Extreme.

706 Views 3 Replies Latest reply: Apr 18, 2012 1:13 PM by Tesserax RSS
macdrewb Calculating status...
Currently Being Moderated
Apr 18, 2012 8:13 AM

Something in Airport is blocking a required port for Microsoft Lync screen sharing to work. When I'm plugged directly into the modem it works fine, but when I'm going through the wireless router I'm getting a network error. All other features of Lync work fine.


There is information here about making sure Lync works on a network: c-online.aspx


but I am unable to figure out how to connect this information to what I'm seeing in Airport Utility.


other info that might be relevant??


Been hitting my head against a wall with this problem. Office 365 support and Apple technical support both gave up.

  • Tesserax Level 8 Level 8 (47,575 points)

    Office 365 support and Apple technical support both gave up.

    That alone may be a hard act to follow and may indicate that Microsoft does not support all consumer routers for Microsoft Lync.


    However, it is important to understand that your 802.11n AirPort Extreme Base Station (AEBSn), like most consumer routers, does NOT block outgoing traffic from your local network, but DOES block all unsolicated inbound traffic from the Internet.


    The first link you provide identifies that firewall ports that need to be open to pass Lync traffic in/out of your AEBSn to work.


    Typically, you configure the AirPort for Port Mapping to do this. The following is the basic instructions to configure your AEBSn for Port Mapping. The process takes two basic steps: 1) Configure the local network client that will need to communicate with a remote service with a static Private IP address, and 2) Configure the AEBSn's NAT firewall to open the required ports.



    AEBSn - Port Mapping Setup

    To setup port mapping on an 802.11n AirPort Extreme Base Station (AEBSn), either connect to the AEBSn's wireless network or temporarily connect directly, using an Ethernet cable, to one of the LAN port of the AEBSn, and then use the AirPort Utility, in Manual Setup, to make these settings:


    1. Reserve a DHCP-provided IP address for the host device.

    AirPort Utility > Select the AEBSn > Manual Setup > Internet > DHCP tab

    • On the DHCP tab, click the "+" (Add) button to enter DHCP Reservations.
    • Description: <enter the desired description of the host device>
    • Reserve address by: MAC Address
    • Click Continue.
    • MAC Address: <enter the MAC (what Apple calls Ethernet ID if you are using wired or AirPort ID if wireless) hardware address of the host computer>
    • IPv4 Address: <enter the desired IP address>
    • Click Done.


    2. Setup Port Mapping on the AEBSn.

    AirPort Utility > Select the AEBSn > Manual Setup >Advanced > Port Mapping tab

    • Click the "+" (Add) button
    • Service: <you can ignore this option>
    • Public UDP Port(s): 3478, 50000-59999
    • Public TCP Port(s): 443, 5223
    • Private IP Address: <enter the IP address of the host device you established above>
    • Private UDP Port(s): 3478, 50000-59999
    • Private TCP Port(s): 443, 5223
    • Click "Continue"


  • Tesserax Level 8 Level 8 (47,575 points)

    How do I find a MAC address? Not sure if this complicates things, but I'm managing the Airport through the Airport Utility on my MacBook Pro, but I'm connecting to Lync on a separate Windows 7 PC, so I think I need to add the address of the PC????

    Yes, you will want to enter the MAC address of the PC that is the Lync client as this is the device that you want to open the ports for. You also want the MAC address of the appropriate network interface that you connect this PC to the local network with: Ethernet or wireless.


    To find the MAC address: Start > Enter cmd in the Search box. This should find cmd.exe. > At the command box prompt, enter: ipconfig /all > Look for the appropriate adapter, and then, look at the value after Physical Address. This is the MAC address that you will need.


    Also be aware that Windows 7 has a software firewall as well. You will either need to disable it (not recommended) or open the same ports on this firewall.


    Also, when you say enter the desired IP address, how do I know what that is?

    This can be any Private IP address currently used by your local network. By default, the AEBSn's DHCP server will hand out these addresses in the thru range. You can pick any address in this range for the DHCP Reservation. That way, whatever address you use, will not be provided to any other network client.


    As a side question, would it be worthwhile trying to run in DHCP only mode? Or is that not even worth testing?

    The DHCP only mode is basically intended where you have a situation where your ISP provides you with one or more static Public IP addresses that you want to assign to specific devices on your local network. A good example is if you have a series of servers (web, email, etc.) that you need to be accessed from the Internet. In this mode, your AEBSn's NAT service will be disabled and ALL devices on your network would be exposed. I would recommend this setting unless this is what you networking requirements demand.


More Like This

  • Retrieving data ...

Bookmarked By (0)


  • This solved my question - 10 points
  • This helped me - 5 points
This site contains user submitted content, comments and opinions and is for informational purposes only. Apple disclaims any and all liability for the acts, omissions and conduct of any third parties in connection with or related to your use of the site. All postings and use of the content on this site are subject to the Apple Support Communities Terms of Use.