SPN Need Help

[er.ashish]

We have 3different webservices running on one server, lets say
Service_A
Service_B
Service_C

Each of these services run under their own Application Poll A, B and
C.
Now all the services run under the same Domain USer Idebtity of
"Domain1\User1"

My question is how the SPN should set for these 3 services?
Also what would be the URL for the three services for call from client
Proxy?

Thanks,
Ashish