DB2 backups are failing with error code 6 ,25, 13

Do you mean 3105408?  I have no idea how that relates to your original problem, but I'm glad you got a solution!

Backup and Duplication jobs to and from an Media Server Deduplication Pool (MSDP) appear to hang or take an extended period of time to complete.
 http://symantec.com/docs/TECH201423

hi All,

This problem was resolved via NETBACKUP EEB.

For version 2.5.2 we have the EEB 310548.

Thanks, anish

In any way related to this post?

https://www-secure.symantec.com/connect/forums/db2-backup-are-failing-error-code-6-could-be-caused-due-client-read-timeout 
 

Are you (still) using a backup network? No way to troubleshoot this without access or co-operation from sysadmins. Please work with AIX admins and ask them for output of the following commands on DB2 client:

bpclntcmd -self

bpclntcmd -pn

After this, check bprd log on master server for incoming connection request from client.
See if master is resolving the client's IP address to same hostname that is in the DB2 policy's Client list.

 *** PS:
Any reason why you stopped responding to this post?
 https://www-secure.symantec.com/connect/forums/client-backup-failing-error-25

I think you'll have better luck with this thread in the NetBackup forum as you're troubleshooting DB2 backups and not really Appliances here.