HP-UX IPv6 Transport Administrator's Guide for TOUR 2.0 (April 2004, rev 2)

IPv6 Addressing and Concepts
Networking Terminology
Chapter 6 67
The interface name may include a colon (:), followed by an interface
index number that denotes the interface number. The interface index
number 0 is the first interface number for a card/encapsulation type and
is known as the primary interface. The interface name lan0 is equivalent
to lan0:0. The syntax is as follows:
nameX [: interface-index-number ]
In the preceding syntax, name is the class of the interface. Valid name is
lan (Ethernet LAN). X is the Physical Point of Attachment (PPA).
interface-index-number is the number of the interface.
You must configure the primary interface for a LAN card before you
can configure subsequent interfaces, known as secondary interfaces,
for the same card. For example, you must configure lan0 before you
configure lan0:1 and lan0:2.