Subject: Re: always print IPv4 alias addresses
To: Erik E. Fair <firstname.lastname@example.org>
From: None <email@example.com>
Date: 04/29/2001 12:21:19
>>Sounds good to me. The whole notion of "aliases" seems silly to me,
>>really... they're just addresses on an interface. I think the only
>>reason we have "alias" is because ifconfig and its ioctls were poorly
>>designed in the first place :-)
bsdi4 changed ifconfig(8) to some degree to achieve this. i have
trouble remembering the exact syntax and/or the behavior.
>Um, well, there is the question of what IP address gets stuffed into
>a packet without one (i.e. most applications don't bother to set one,
>so you get one from the interface that the routing table decides to
>send the packet out), and that marks the difference between the
>interface's "address" and an "alias".
4.4BSD IPv4 implementation basically assumes that there's only
one address on a interface. the code that manipulates rt->rt_ifa
is one example, and the whole notion of "alias" is another example.
not sure if it is a good thing or a bad thing. if we want to change
this for IPv4 codepath, we need a whole lot of changes. IPv6 removed
the assumption, and we have a lot of fun/discussion with source address