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Multiple Networks

Updated: 21 May 2010 | 7 comments
Peter Bevington's picture
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The NBU help files describes a senario where clients and/or Servers have
multiple network infterface cards for use on Production and Backup
networks. Those solutions suggest to make use of the 'Use Specificed
Network Interface' configured to use the backup NIC

In my environment, I have both a production and backup networks available
to be used for backup/restore purposes. The backup and production networks
have limited connectivity between them, this is controlled by access
control lists which is handled by our telecoms department.

I have many clients, most of which are located on the both the production
and backup networks. However, some clients can only be connected to the
production network. My Master server is configured to use the Backup NIC
as its' specified network interface. No clients or media server have this
configuration entry added and hence use the NIC determined by the O.S.

The clients which are only available on the production network fail to
backup with various connection type problems.

What is the best practice to follow and how should this be configured in
my environemt to allow successful backups and restore over both production
and backup networks.

Comments

Simon Caudwell 2's picture
06
Nov
2006
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Peter, by enabling that option on your Master Server and specifying the backup network interface, it means that your clients without a backup NIC will not communicate with the Master Server as it can no longer talk to them via the production net. It is trying to talk to those clients via the backup network only and they have no connection to it.

Peter Bevington's picture
06
Nov
2006
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Hi Simon,

Yes I understand that enabling that option would stop any client only on the production network from 'working'.

However, this option is a necessity as the previous DNS configuration, regarding Master & Media servers is an unknown. Present DNS administartors assure me that DNS (and NBU servers entries) is configured correctly. If the specificed network interface is not set to the backup environment NIC, then backups which use the backup network will fail.

I know this is a DNS type issue but cannot determine how it was previously configured. NBU documentation points towards using specified NIC to ensure the backup network is used as a priority.

BTW, nice to hear from you.

Dennis Strom's picture
06
Nov
2006
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you want the master server to communicate on both networks. your master will be able to figure out which NIC card to use using dns, nis or ldap whatever you are useing. If you want to specifiy a specific network to use do it on the client side.

Peter Bevington's picture
06
Nov
2006
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Thank you for your comments.

I have also been able to backup clients which are not on the backup network via configuring comm's routes (via ACLs) and using their FQDN for clients which are behind firewall's or on different domains etc but am still having issues with the very few clients which are on the 'standard' production network only.

Simon Caudwell 2's picture
06
Nov
2006
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Peter,

Don't believe your DNS administrators! ;o) You're correct about it being a DNS issue.

Run bpclntcmd from the clients, the master and the relevant media servers. Only put in the short name. If they're resolving via DNS as they should, the FQDN and the correct IP address will be returned. Double-check any responses and confirm them.

Any returns other than what should be expected will mean one of three things 1) A wrong entry in DNS, 2) an extra incorrect DNS entry taking preference (perhaps because it gets found first due to your domain lookup listing, or 3) incorrectly configured DNS settings on the NIC.

When did this change? Your environment relies on DNS being right for NBU to work.

PS. Still happy being a Veritas Admin?!?!?? ;o)

Peter Bevington's picture
06
Nov
2006
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Thanks once more, I will investigate this further with our DNS administrator.

And Yes, NetBackup admin is fun, on the whole ;-)

Peter Bevington's picture
07
Nov
2006
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This is all related to DNS. Although not directly a NetBackup issue, nor a DNS issue. It is VERY impoprtant to have full documenation to identify the correct NetBackup-DNS configuration for your particular environment to be able to referr to if all goes wrong in the future.