We have an internal portal on SharePoint Server 2010. For example portal.abc.com. We are using Windows authentication (NTLM).
When users access the portal from a joined computer in an Active Directory domain, everything works fine, however, we have some users that work with iPads using mobile Safari.
Users need only read the information on the portal. They use VPN (PPTP). Every time when these users try to log into the portal, SharePoint prompts for credentials. Every time.
Does anyone know how to fix it? I'll be glad to any suggestions as to prevent users from such inconveniences.