Which two statements are true about the primary address on an interface? (Choose two)
A.
It is the address used by default as the local address for broadcast and multicast packets sourced locally and sent out of the interface
B.
You use the primary address when you have multiple IP addresses belonging to the same subnet on the same inteface
C.
It can be useful for selecting the local address used for packets sent out of unnumbered interfaces when multiple non-127 addresses are configured on the loopback interface
D.
By default, the primary address on an interface is selected as the nmerically highest local address configured on the interface
// Primiry address :
**An interface’s primary address is used by default as the local address for broadcast and multicast packets sourced locally and sent out the interface. An interface’s preferred address is the default local address used for packets sourced by the local router to destinations on the subnet.// **The primary address flag also can be useful for selecting the local address used for packets sent out unnumbered interfaces when multiple non-127 addresses are configured on the loopback interface, lo0. By default, the primary address on an interface is selected as the numerically lowest local address configured on the interface.
Source :
http://www.juniper.net/techpubs/en_US/junos13.3/topics/usage-guidelines/interfaces-configuring-default-primary-and-preferred-addresses-and-interfaces.html