Netbackup failure in LDOM solaris

Hi

We have solaris ldoms configured in which backup team has reported failure in some of the ldoms.

Details are: 

stpsn5500# ldm list
NAME             STATE      FLAGS   CONS    VCPU  MEMORY   UTIL  UPTIME
primary          active     -n-cv-  SP      8     8G       0.4%  645d 5h
stpld5501        active     -n----  5000    8     8G       0.3%  339d 22h
stpld5502        active     -n----  5001    4     2G       0.5%  339d 22h
stpld5503        active     -n----  5002    4     2G       0.4%  339d 22h
stpld5509        active     -n----  5008    4     2G       0.3%  339d 22h
stpld5511        active     -n----  5010    4     2G       0.3%  339d 22h

Kindly let me know, how to check the status of the backup and steps to troubleshoot the backup failures.

I have tried to ssh ldoms but it shows connection refused;

# ssh stpld5502
ssh_exchange_identification: Connection closed by remote host