Here is how I do different IP for the same SD.  In my case, remote clients
access the SD via the gateway (public IP address which is forwarded
from my gateway to the SD) and local clients access the local IP address
(in the 192.168. block).

I have slightly altered this config from my actual, but it should illustrate how
to do this.

>>From bacula-dir.conf

Storage {
 Name       = DLTRemoteTLS
 Address    = storage1.example.org
 SDPort     = 9103
 Device     = DLT
 Media Type = DLT
}

# Definition of DLT tape storage device
Storage {
 Name       = DLT
 Address    = bacula.example.org
 SDPort     = 9103

 Device     = DLT
 Media Type = DLT
}

That's it.  Note that both Storage resources refer to the same Device.
Both Storage resources have different Address values.  Use FQDN
and point each to different IP addresses.

In my case, bacula.example.org points to 192.168.1.12 and
DLTRemoteTLD refers to storage1.example.org, which is a public IP address.

Then in bacula-sd.conf, I define the DLT device.

Device {
 Name                    = DLT
 Description             = QUANTUM DLT7000 1624
 Media Type              = DLT
 Archive Device          = /dev/nsa0
}

Nothing special.  But it's clever.  Someone else showed me how to do it.

Does that give you something to think about?

--
Dan Langille
http://langille.org/