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NetBackup Communication ??? How does it do

Created: 05 Aug 2012 | 8 comments
V4's picture

Just wondering How Netbackup Master / Media  and Client connects to each other (IP or Hostname)

Surfed around but couldn't get detailed architecture for this.

Also How does it deals in case of DHCP with 2 different IP subnet as scopes and provides IP to same clients' (Wired and Wireless with same lease period).

I found DHCP timeout under NBU host properties but couldn't get any idea what timeout should be specified here. As all the clients will have recieved IP(s) on different dates with same lease of 7 days.

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Marianne's picture

NetBackup will use whatever name resolution is used at OS level. 

If using DNS, ensure that forward and reverse lookup is enabled. With DHCP I have found that reverse lookup is not always updated in DNS. 

Something else to keep in mind is NBU host_cache. You may have to refresh host_cache on all servers and clients after new DHCP IP's have been obtained. See these TNs for info:

NBU works best with fixed IP addresses, which is normally the case in a Server environment. This is what NBU is designed for - to backup all the servers in an organization.

You may also want to add bpclient -dynamic_address 1 entries for all clients on DHCP. See

Another helpful TN where servers have multiple NICs:

Supporting Storage Foundation and VCS on Unix and Windows as well as NetBackup on Unix and Windows
Handy NBU Links

V4's picture

Marianne issue is that. Wireless has Different range of IP scope within DHCP and Wired network has different range of address scope. both have same lease period.

User keep on switching between Wifi and wired. During this if backup is initiated, NBU gets confused and job fails with status 58

revarooo's picture

Thats a break in comms if the IP is changing. Once connection is established it should be stable. Switching  IP is a drop in the connection.

V4's picture

Do you mean, if backup started with 192.168.42.xx ip and after 30 mins client switched to WIFI (got new ip 192.168.43.xx)

during IP change backup goes in incomplete state. This needs to be resumed, more over many times this doesn't work. Is there any way we can bind communication to check for hostname which are static.

how frequent does NBU refreshes it's cache of hostname and ip

Andy Welburn's picture

Or are you actually talking about someones laptop? If so, maybe DLO would be more appropriate?

Personally I would not want *any* production server jumping from one network to another at the drop of a hat!

Marianne's picture

Have you had a look at any of the TNs that I posted above?

Extract from TECH136792 :

Each cache entry has a life span of one hour, for both successful and unsuccessful resolution attempts, to suppress the otherwise repeated lookups. Accordingly, NetBackup may not recognize any changes to /etc/hosts or DNS for up to one hour.

NBU is actually intended for Server backups. 
As per Andy's post, best to have a look DLO for desktop and laptops.

Supporting Storage Foundation and VCS on Unix and Windows as well as NetBackup on Unix and Windows
Handy NBU Links

V4's picture

Just checking with Dynamic IP properties from TN.

I agree NBU being Enterprise product, is intended for Server backup only. But SCL makes it confuse with Endpoint being certified and no where there are official statement for not using NBU within endpoints. Customer are keen to see this.

V4's picture

Andy you got the catch. it's endpoint not the server. Endpoints are protected via DeDupe

I tried with Network WAN resiliency feature too if that helps. But it didn't worked.

It works on same network only but not with two network with same client