ACX5048,ACX5096,SRX Series,vSRX. The Internet Protocol (IP) specifies a loopback network with the (IPv4) address 127.0.0.0/8. Most IP implementations support a loopback interface (lo0) to represent the loopback facility. Linphone is an open source SIP client for HD voice/video calls, 1-to-1 and group instant messaging, conference calls etc. Available for iOS, Android, Windows, macOS and GNU/Linux.

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Original KB number: 10041

Summary

This guide enables your Skype for Business users to IM and talk with Skype for Business contacts in other organizations, and also to Skype users who are signed in with a Microsoft account (formerly Windows Live ID). And you want to set it up so that everything works right the first time.

Note

This is not the same as setting up external contacts in Outlook or sharing my website with outside people. Because each type of external contact has a different purpose.
A Skype for Business external contact is someone outside your organization who's using a compatible IM and conferencing client - either Skype for Business or Skype. However, all that's required for Outlook external contacts or website sharing is a valid email address. For more information, see Collaborating with people outside your organization.

First, we'll ask you a few quick questions about your Microsoft 365 setup. Then we'll give you all the information you need to complete up to four tasks.

This should take less than an hour of your time, plus up to 24 hours (for network propagation) if you haven't turned on external communications yet.

Check your Microsoft 365 version

To check your Microsoft 365 version, sign in and go to Admin > Licensing.

Lync for mac download

What version of Microsoft 365 do you have?

If the version is Small Business

Custom domain (Small Business)

Microsoft 365 creates a domain for you when you sign up (the domain name includes .onmicrosoft.com). But most companies prefer to use their own domain, like fabrikam.com, for their business email addresses and website.

If your current domain name ends in .onmicrosoft.com, you don't have a custom domain. For more information, see Add a domain to Microsoft 365.

Are you using a custom domain with Office 365?

  • If yes, see Custom domain status (Small Business).
  • If no, see Turn on external communications.

Custom domain status (Small Business)

To set up your custom domain, sign in and select Email address in the Getting Started pane. (If you don't see the Getting Started pane, select Setup > Open the Getting Started pane.) For more information, see Add a domain to Microsoft 365.

Have you already set up your custom domain?

  • If yes, see Test your custom domain (Small Business).
  • If no, see Set up your custom domain (Small Business).

Test your custom domain (Small Business)

After that make sure everything works as expected by running Microsoft 365 Skype for Business Domain Name Server (DNS) Connectivity Test.

When you've confirmed that your custom domain is set up correctly, continue to the next step.

Turn on external communications (Small Business)

Sign in to Microsoft 365, and go to Admin > Service Settings > IM, meetings and conferencing > External communications. For more information, see Allow users to contact external Skype for Business users.

First, if you haven't already done so, turn on external communications for everyone in your organization.

Important

It may take up to 24 hours for your changes to take effect. You can save your current progress and return if you need to.

Communicate with Skype for Business users in other organizations (Small Business)

If you want to communicate with external Skype for Business users, you'll need to make sure the admin in the other organization has set up external communications as well.

Do you want your users to communicate with Skype for Business users in other organizations?

  • If yes, see Contact the Skype for Business admin in the other organization.
  • If no, see Inform your user.

Set up your custom domain (Small Business)

Set up your custom domain

It's best to take the time and set up your custom domain now. The rest of this process will make much more sense after you've done so. Our goal: to help you get set up right the first time, so you can focus on your work and not on your software.

To set up your custom domain, sign in and select Email address in the Getting Started pane. (Go to Setup > Open the Getting Started pane if you don't see it.) For more information, see Add a domain to Microsoft 365.

Test the custom domain

After that make sure everything works as expected by running Microsoft 365 Skype for Business Domain Name Server (DNS) Connectivity Test.

Turn on external communications (Small Business)

Sign in to Microsoft 365, and go to Admin > Service Settings > IM, meetings and conferencing > External communications. For more information, see Allow users to contact external Skype for Business users.

First, if you haven't already done so, turn on external communications for everyone in your organization.

Important

It may take up to 24 hours for your changes to take effect. You can save your current progress and return if you need to.

Communicate with Skype for Business users in other organizations (Small Business)

If you want to communicate with external Skype for Business users, you'll need to make sure the admin in the other organization has set up external communications as well.

Download

Do you want your users to communicate with Skype for Business users in other organizations?

  • If yes, see Contact the Skype for Business admin in the other organization.
  • If no, see Inform your user.

Turn on external communications

Sign in to Microsoft 365, and go to Admin > Service Settings > IM, meetings and conferencing > External communications. For more information, see Allow users to contact external Skype for Business users.

First, if you haven't already done so, turn on external communications for everyone in your organization.

Important

It may take up to 24 hours for your changes to take effect. You can save your current progress and return if you need to.

Communicate with Skype for Business users in other organizations

If you want to communicate with external Skype for Business users, you'll need to make sure the admin in the other organization has set up external communications as well.

Do you want your users to communicate with Skype for Business users in other organizations?

  • If yes, see Contact the Skype for Business admin in the other organization.
  • If no, see Inform your user.

Contact the Skype for Business admin in the other organization

To communicate with external Skype for Business users:

  1. Contact the admin in the other organization using this email template.

  2. Once they've turned on external communications, you and the other admin can add each other as Skype for Business contacts to test things out.

  3. After you and the other admin have verified that you can use Skype for Business to communicate with each other, go to the next step.

  4. Use this email template to let your users know how adding external contacts works in your organization. The template includes links to these important end-user topics:

Can you now communicate with external Skype for Business or Skype contacts?

  • If yes, congratulations, you're now set up for Skype for Business Online external communications.
  • If no, see What to do if external communications still doesn't work.

What to do if external communications still doesn't work

We're sorry you're having trouble setting up external communications.

If you've completed all the tasks in this guide, are able to sign in to Microsoft 365 using your custom domain name, and still can't communicate with outside users, here are some additional resources:

  • Search the Microsoft 365 Community forums.
  • Contact support.

If the version is Midsize Business

Custom domain

Microsoft 365 creates a domain for you when you sign up (the domain name includes .onmicrosoft.com). But most companies prefer to use their own domain, like fabrikam.com, for their business email addresses and website.

If your current domain name ends in .onmicrosoft.com, you don't have a custom domain. For more information, see Add a domain to Microsoft 365.

Are you using a custom domain with Microsoft 365?

  • If yes, see Custom domain status.
  • If no, see Turn on external communications (Midsize Business and Enterprise).

Turn on external communications (Midsize Business and Enterprise)

First, if you haven't already done so, turn on external communications for everyone in your organization and configure any domain exceptions you may want to implement. If you want to communicate with other Lync or Skype for Business organizations, it's recommended that you add your partner's organizations domain to the list of Allowed domains.

Sign in to Microsoft 365, and go to Admin Center > Settings > Services & add-ins > Skype for Business > External communications. For more information, see Allow users to contact external Skype for Business users.

Important

It may take up to 24 hours for your changes to take effect. You can save your current progress and return if you need to.

Communicate with Skype for Business users in other organizations

If you want to communicate with other Skype for Business organization, you'll need to make sure the admin in the other organization has set up external communications as well.

Communicate with Skype users

If you want to allow your Skype for Business Online users to communicate with Skype consumer users? If so, make sure the following switch is enabled:

Have you allowed your users to communicate with Skype for Business users in other organizations?

  • If yes, see Contact the Skype for Business admin in the other organization.
  • If no, see Inform your user.

If the version is Enterprise

Custom domain (Enterprise)

Microsoft 365 creates a domain for you when you sign up (the domain name includes .onmicrosoft.com). But most companies prefer to use their own domain, like fabrikam.com, for their business email addresses and website.

If your current domain name ends in .onmicrosoft.com, you don't have a custom domain. For more information, see Add a domain to Microsoft 365.

Are you using a custom domain with Microsoft 365?

  • If yes, see Custom domain status.
  • If no, see Turn on external communications (Midsize Business and Enterprise).

Custom domain status

To set up your custom domain, sign in and go to Admin > Setup. For more information, see Add a domain to Microsoft 365.

Have you already set up your custom domain?

  • If yes, see Turn on external communications (Midsize Business and Enterprise).
  • If no, see Setup and test your custom domain.

Setup and test your custom domain

It's best to take the time and set up your custom domain now. The rest of this process will make much more sense once you're done adding your own domain. Our goal: to help you get set up right the first time, so you can focus on your work, and not on your software.

To set up your custom domain, sign in and go to Admin > Setup. For more information, see Add a domain to Microsoft 365.

Test your custom domain

Run the domain troubleshooter:

  1. Go to the Microsoft 365 admin center and select Domains.

  2. Select your custom domain name, and then select Fix Issues.

Now make sure everything works as expected by running the domain troubleshooter in the Microsoft 365 admin center.

When you see a message that says everything is set up correctly, you can continue the next step.

If you have a firewall or proxy setup in your environment, make sure to configure it to exclude the Office 365 URLs and IP address ranges. If you need help with this step, contact Microsoft 365 Support.

Turn on external communications

Details

Sign in to Microsoft 365, and go to Admin Center > Settings > Services & add-ins > Skype for Business > External communications. For more information, see Allow users to contact external Skype for Business users.

First, if you haven't already done so, turn on external communications for everyone in your organization. If you want to communicate with other Lync or Skype for Business organizations, it's recommended that you add your partner's organizations domain to the list of Allowed domains.

Important

It may take up to 24 hours for your changes to take effect. You can save your current progress and return if you need to.

Communicate with Skype for Business users in other organizations

Details

What Is Lync For Mac

If you want to communicate with external Skype for Business users, you'll need to make sure the admin in the other organization has set up external communications as well.

Do you want your users to communicate with Skype for Business users in other organizations?

  • If yes, see Turn on external communications (Midsize Business and Enterprise).
  • If no, see Custom domain.

Inform your user

The last step:

  • Use this email template to let your users know how adding external contacts works in your organization. The template includes links to these important end-user topics:

Can you now communicate with external Skype for Business or Skype contacts?

  • If yes, congratulations, you're now set up for Skype for Business Online external communications.
  • If no, see What to do if external communications still doesn't work.
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Original KB number: 10054

Summary

Note

  • To use this guide, you must have a Skype for Business sign-in name and password from an organization that uses Microsoft 365 Apps for business.
  • If you're an Office 365 admin, see Troubleshooting Skype for Business Online sign-in issues for admins.

We'll begin by asking you questions about your installation and the symptoms you're experiencing. Then we'll take you through a series of troubleshooting steps and configuration checks that are specific to your situation.

Important

Some troubleshooting steps are different depending on the type of installation you have. Please complete each troubleshooting step, even if it doesn't seem to apply to you.

The amount of time you spend will depend on the type of installation you have, and the causes of your sign-in issues.

Test your sign-in credentials

The first step is to try to sign in with your credentials in another location: Microsoft 365 Web Scheduler.

In most cases, both your sign-in address and user name look like one of these examples:

  • someone@example.com
  • someone@example.onmicrosoft.com

Can you sign in to Microsoft 365 Web Scheduler at https://sched.lync.com?

  • If yes, see Sign in with your corrected sign-in address.
  • If no, see Can't sign in to Microsoft 365 Web Scheduler.
  • If you forgot your password, see Contact your workplace technical support for a new password.

Sign in with your corrected sign-in address

If you're able to successfully sign in to Microsoft 365 Web Scheduler, try signing in again with the same type of credentials:

someone@example.com or someone@example.onmicrosoft.com

Were you able to sign in?

  • If yes, congratulations, you've resolved your sign-in issue!
  • If no and you need both a sign-in address and user ID, see Enter your user ID.
  • If no, and you got some other error, see Contact your workplace technical support for a new password.

Contact your workplace technical support for a new password

If you've forgotten your password or it's no longer working, use the Microsoft Online Password Reset site to request a new password from your workplace technical support team- typically the people who set up your account for you.

Important

If the password reset site doesn't work for you, contact your workplace tech support team directly.

Once you have a new password, try signing in again.

Did this solve your problem?

  • If yes, congratulations, you've resolved your sign-in issue!
  • If no, see Sign in on another device.

Sign in on another device

Are you able to sign in on another computer, or on a tablet or smartphone?

  • If yes, see Type of device.
  • If no, see Sign in on another network.
  • If you don't have access to another device right now, Type of device.

Sign in on another network

Can you sign in on a different network-for example, at home, or at a public wireless access point?

  • If yes, see Contact your workplace technical support
  • If no, see Type of device that you use to sign in.
  • If you don't have access to a different network right now, see Contact your workplace technical support

Type of device

What type of devices are you using to sign in?

  • For Windows computer, laptop, or tablet, see Synchronize your system clock with the network (Windows computer or laptop).
  • For Mac computer or laptop, see Synchronize your system clock with the network (Mac computer or laptop).
  • For Smartphone, see Update Skype for Business on the smartphone or tablet.
  • For iPad or Android tablet, see Update Skype for Business on the smartphone or tablet.

Type of device that you use to sign in

If you can't sign in on another network, the issue might be with the client you're using.

What type of devices are you using to sign in?

  • For Windows computer, laptop, or tablet, see [- If no, see Delete Skype for Business sign-in information.
  • For Mac computer or laptop, see Delete Skype for Business for Mac sign-in information.
  • For Smartphone, see Configure Skype for Business Online connection settings manually (Skype for Business for mobile devices).
  • For iPad or Android tablet, see Configure Skype for Business Online connection settings manually (Skype for Business for mobile devices).

Synchronize your system clock with the network (Windows computer or laptop)

Make sure your system clock shows the correct time, and then try signing in again.

Details

Update your computer's system time:

Windows 8

  1. Go to a web site that shows Coordinated Universal Time (UTC).

  2. Go to Setting > PC Settings > Time and Language.

  3. Note your UTC offset, and compare your device's time to that shown on the website.

If you need to update your device's time:

  1. Turn off Set time automatically and tap Change.
  2. Update the time and tap Change.
  3. Try signing in again.

Windows 7

  1. Go to a web site that shows Coordinated Universal Time (UTC).

  2. Go to Control Panel > Date and Time, and note the UTC offset for your location.

  3. If you need to, choose Change date and time and update your computer's clock.

  4. Try signing in again.

Did this solve your problem?

  • If yes, congratulations, you've resolved your sign-in issue!
  • If no, see Delete Skype for Business sign-in information.

Desktop Setup

Make sure you have the most current version of the Microsoft Online Services Sign-in Assistant.

Did this solve your problem?

  • If yes, congratulations, you've resolved your sign-in issue!
  • If no, see Delete Skype for Business sign-in information.

Update Skype for Business

Make sure the user has the most current version of Skype for Business.

Did this solve your problem?

  • If yes, congratulations, you've resolved your sign-in issue!
  • If no, see Delete Skype for Business sign-in information.

Delete Skype for Business sign-in information

For more information, see How to troubleshoot being unable to sign in to Skype for Business.

Did this solve your problem?

  • If yes, congratulations, you've resolved your sign-in issue!
  • If no, see Configure connection settings manually.

Synchronize your system clock with the network (Mac computer or laptop)

Make sure your system clock shows the correct time, and then try signing in again.

Details

Follow these steps:

  1. Go to a web site that shows [Coordinated Universal Time (UTC).
  2. Go to Apple > System Preferences.
  3. In the Date & Time pane, select the Date & Time tab.
  4. Note the UTC offset for your location.
  5. If you need to, update your computer's clock, and then try signing in again.

Did this solve your problem?

  • If yes, congratulations, you've resolved your sign-in issue!
  • If no, see Update Skype for Business.

Update Skype for Business

Make sure your computer has the most recent version of Skype for Business.

Did this solve your problem?

  • If yes, congratulations, you've resolved your sign-in issue!
  • If no, see Delete Skype for Business sign-in information.

Delete Skype for Business for Mac sign-in information

Make sure that previously saved sign-in information isn't blocking your current sign-in attempt.

Details

First, delete the following:

  • Users/Home Folder/Library/Caches/com.microsoft.Skype for Business
  • Users/Home Folder/Documents/Microsoft User Data/Microsoft Skype for Business History

Then delete any corrupted or cached certificates:

  1. Open the Keychain Access certificate management utility. To do this, in Finder, select Applications, select Utilities, and then select Keychain Access. Or, search for Keychain Access by using Spotlight.
  2. In the left pane, select login, and then select Certificates.
  3. In the right pane, find any certificate named Unknown or Communications Server, select it, and then delete it. Note that you may have to unlock your keychain by using your password.
  4. Close Keychain Access.
  5. Restart Skype for Business for Mac.

Did this solve your problem?

  • If yes, congratulations, you've resolved your sign-in issue!
  • If no, see Configure connection settings manually.

Update Skype for Business on the smartphone or tablet

For

Go to the app store for your device and check for updates to the currently installed version of Skype for Business.

Did this solve your problem?

  • If yes, congratulations, you've resolved your sign-in issue!
  • If no, see Configure Skype for Business Online connection settings manually (Skype for Business for mobile devices).
Lync

Configure Skype for Business connection settings manually

Manually add Skype for Business server settings and try signing in again.

Details

Manually add Skype for Business server settings:

  1. Go to Skype for Business options > Personal.

  2. Under My account, select Advanced, and then select Manual configuration.

  3. Enter sipdir.online.lync.com:443 in both boxes, and then select OK > OK.

  4. Sign out, and then try signing back in.

Did this solve your problem?

  • If yes, see Issue temporarily resolved (Clients and devices).
  • If no, see Contact your workplace technical support.

Configure Skype for Business connection settings manually

Manually add Skype for Business server settings, and then try signing in again.

Details

Ask the user to follow these steps:

  1. Select Advanced.
  2. Under Authentication, clear the Use Kerberos check box.
  3. Under Connection Settings, select Manual configuration.
  4. In both the Internal Server Name box and the External Server Name box, type or paste sipdir.online.lync.com:443.
  5. Select OK.

Did this solve your problem?

  • If yes, see Issue temporarily resolved (Clients and devices).
  • If no, see Contact your workplace technical support.

Issue temporarily resolved (Clients and devices)

We're glad to hear you're back in service.

To help your organization find out why Skype for Business can't automatically sign in, contact your workplace technical support-typically the person who sent you email about how to get set up with Office 365.

Configure Skype for Business Online connection settings manually (Skype for Business for mobile devices)

Manually add Skype for Business Online server settings, and then try signing in again.

Details

Manually add Skype for Business server settings:

  1. On the Skype for Business sign-in screen, tap More Details (Windows) or Show Advanced Options (iPhone, iPad, or Android).
  2. Turn off Auto-Detect Server.
  3. In both the Internal Discovery Name and External Discovery Name boxes, enter https://webdir.online.lync.com/Autodiscover/autodiscoverservice.svc/Root
  4. Select Sign In.

Did this solve your problem?

  • If yes, see Issue temporarily resolved (Clients and devices).
  • If no, see Configure Skype for Business Server connection settings manually (Skype for Business for mobile devices).

Contact your workplace technical support

We're sorry, but we couldn't resolve your sign-in issue. For more troubleshooting, contact your workplace technical support-typically the person who sent you email about how to get set up with Office 365.

Enter your user ID

If Skype for Business asks you for your user ID, in most cases it is the same as your sign-in address-for example, bobk@contoso.com.

If that doesn't work, try the same credentials you use when signing in to your organization's network-for example, CONTOSObobk.

Did this solve your problem?

  • If yes, congratulations, you've resolved your sign-in issue!
  • If no, see Sign in on another device.

Microsoft Lync For Mac

Update Skype for Business Windows Store app

Make sure you have the most current version of Skype for Business Windows Store app:

  1. On the Start screen, tap Store

  2. Search for Skype for Business, and install the update if one is available.

  3. Try signing in again.

Did this solve your problem?

  • If yes, congratulations, you've resolved your sign-in issue!
  • If no, see Delete Skype for Business sign-in information.

Clear the DNS cache

Make sure that previously save network information is not blocking your sign-in attempt, and then try signing in again.

Windows 8

Clear the DNS cache (summary)
  • Run the Command prompt app as an administrator, and enter ipconfig /flushdns.
Clear the DNS cache (details)
  1. Swipe in from the right or point to the upper right of the screen.
  2. Choose Search, and then type command.
  3. Select the Command prompt app, and then swipe up from the bottom or right click for options.
  4. Choose Run as administrator, and then choose Yes.
  5. Enter ipconfig /flushdns.

Windows 7, Windows Vista, Windows XP, Windows Server 2008, or Windows Server 2003

Clear the DNS cache
  1. Select Start, and in the Search programs and files box, enter cmd.exe.
  2. Right-click cmd.exe in the search list, and then select Run as administrator.
  3. Enter ipconfig /flushdns.

Did this solve your problem?

  • If yes, congratulations, you've resolved your sign-in issue!
  • If no, see Configure connection settings manually.

Can't sign in to Microsoft 365 Web Scheduler

What kind of error did you get when you tried to sign in to https://sched.lync.com?

Configure Skype for Business Server connection settings manually (Skype for Business for mobile devices)

If the Skype for Business Online manual configuration didn't work, your organization may be using Skype for Business Server.

  • First try signing in with this Skype for Business Server setting: https://webdir.example.com/Autodiscover/ autodiscoverservice.svc/Root where example.com is your domain name.
  • Then try signing in with this Skype for Business Server setting: https://webext.example.com/Autodiscover/ autodiscoverservice.svc/Root where example.com is your domain name.

Details

Manually add Skype for Business server settings:

  1. On the Skype for Business sign-in screen, tap More Details (Windows) or Show Advanced Options (iPhone, iPad, or Android).
  2. Turn off Auto-Detect Server.
  3. In both the Internal Discovery Name and External Discovery Name boxes, enter the webdir server address on the left. For example, if your domain name is contoso.com, enter https://webdir.contoso.com/Autodiscover/autodiscoverservice.svc/Root.
  4. Select Sign In.
  5. If you are not able to sign in, enter the webext server address on the left in both boxes. For example: https://webext.contoso.com/Autodiscover/autodiscoverservice.svc/Root.
  6. Select Sign In.

Did this solve your problem?

  • If yes, see Issue temporarily resolved (Clients and devices).
  • If no, see Contact your workplace technical support.