When installing the Lync Edge server it can fail on step 2 and say:
Host name: tssrvlync003
WARNING! Host not found in topology. All roles will be uninstalled.
Disabling unused roles…
Make sure to configure a DNS suffix, since the computer is not a member of the domain it will look for itself as only the computer name and not with the FQDN.
Configure the DNS Suffix for Edge Servers
1. On the Edge Server computer, click Start, right-click Computer, and then click Properties.
2. Under Computer name, domain, and workgroup settings, click Change settings.
3. On the Computer Name tab, click Change.
4. In the Computer Name/Domain Changes dialog box, click More.
5. In the DNS Suffix and NetBIOS Computer Name dialog box, in Primary DNS suffix of this computer, type contoso.net and then click OK three times.
6. Restart the computer.