A. Change the stub zone to a secondary zone on Server1
B. Open the SOA record for the zone on Server2. Change the Minimum (default) TTL setting to 12 hours.
C. Open the DNS zone for the partner company on Server2. Create a new Route Through (RT) record and a new host (A) record for Server1.
D. Open the primary DNS zone on Server2. Create a new Service Locator (SRV) record and a new host(A) record for Server1.