Bind License to NIC on High Availability

[avayax]

I have an HA environment and I am not sure to what NIC to bind my license to on each of the servers.
I know I need an additional license for each node.

Shall I go:
/usr/local/fop2/fop2_server --register -i em1
or
/usr/local/fop2/fop2_server --register -i em1:ext-ip

em1:ext-ip is my floating cluster IP and em1 the one of machine 1. It is the same MAC so I don't know if it makes a difference at all.

ifconfig
em1 Link encap:Ethernet HWaddr xxxxxxxxxxxx
inet addr:192.168.1.3 Bcast:xxx.xxx.xx.xxx Mask:xxx.xxx.xxx.x

em1:ext-ip Link encap:Ethernet HWaddr xxxxxxxxxxxx
inet addr:192.168.1.1 Bcast:xxx.xxx.xx.xxx Mask:xxx.xxx.xxx.x

Thank you.

[avayax]

I assigned to em1. I think that works fine.

[nicolas]

You can bind to any NIC that has a MAC address. It is not important the role of the card, the only parameter used is the MAC address.