FIM Portal URL is not consistent on all the Servers

Hi All,

Hope you all well,

My Current FIM environment is:-

1). Server A (FIM Portal 1)

2). Server B (FIM Portal 2)

3). Server C (Both FIM Portals pointing to FIM Service Server C)

4). Server  D (FIM Sync Server)

 Now my question is, I am facing error "Service not available" while accessing the FIM Portal 2 or FIM Portal 1 from server C and D. Actually, FIM Portal URL's is not accessible consistently on all the servers. Some time it works, some times not.

I have checked by setting the SPN for FIM Service account but in vain.

For reference Please find the below screen shot.



Any help would be appreciated.

Thanks

ajay kumar