How do I tell Amanda to use a specific network interface if 2 exist on
the system.

I think you define it in amanda.conf like:
define interface eth2 {
    comment "1000 Mbps ethernet"
    use 4000 kbps
}

For instance I would like Amanda to only use the ce4 interface..
ce0: flags=1000843<UP,BROADCAST,RUNNING,MULTICAST,IPv4> mtu 1500 index 2
       inet 10.20.1.181 netmask ffff0000 broadcast 10.20.255.255
       ether 0:3:ba:9a:4f:6f
ce4: flags=1000843<UP,BROADCAST,RUNNING,MULTICAST,IPv4> mtu 1500 index 3
       inet 172.23.1.73 netmask ffffff00 broadcast 172.23.1.255
       ether 0:3:ba:9a:4f:6f
Thanks,
Anderson

===========================================
Yu Chen
Howard Hughes Medical Institute
Chemistry Building, Rm 182
University of Maryland at Baltimore County
1000 Hilltop Circle
Baltimore, MD 21250

phone:  (410)455-1728 (primary)
        (410)455-6347 (secondary)
fax:    (410)455-1174
email:  chen AT hhmi.umbc DOT edu
===========================================

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