Restrict customer network to access specific tenant.
Due to some SOX audit´s that some customers must meet, we are facing problems to meet the restriction of customer network to be allowed to access specific tenant. Fail to meet this requirement let internal users to be able to connect to any office365 tenant inside customer network. And this is bad for audit´s. Google apps implemented this restriction trough some sort of tagging of headers to be sent to google tenants. https://support.google.com/a/answer/1668854?hl=en
Konstantin Ryvkin commented
Please check the "Tenant Restrictions" feature https://docs.microsoft.com/en-us/azure/active-directory/active-directory-tenant-restrictions and see if it meets your needs for this scenario