[afnog] Two IP Addresses on the same Interface

[Phil Regnauld]

Randy Bush (randy) writes:
> > I'd like to configure two routable IP addresses (from different  
> > prefixes) on the same NIC. How can I go about this in FreeBSD?
> 
> from /etc/rc.conf
> 
> ifconfig_em0="inet 147.28.0.62 netmask 255.255.255.0"
> ifconfig_em0_alias0="inet 147.28.0.34 netmask 255.255.255.255"
> ifconfig_em0_alias1="inet 147.28.0.36 netmask 255.255.255.255"

	[...]

> in your case, the alias would have a diff mask than /32 i assume

	He says "different prefixes".  If that's the case, then the
	alias will have the real netmask.

	i.e.:

	ifconfig_em0_alias0="inet 1.2.3.4/27"

	/32 is only used for aliases within the same IP subnet.

	P.