On Thu, Mar 15, 2001 at 06:08:20AM -0800, Caffeinate The World wrote:
> 
> this is what i have in mine:
> 
> # cat /etc/ifconfig.de0
> 23.206.86.53 netmask 0xfffffff8 media 100baseTX
> 23.206.86.55 netmask 0xffffffff alias
> 
> one thing that i've found that was strange was that the netmask for the
> alias as to be 255.255.255.255 or as with the hex above. 

That's only the case when the subnets would be conflicting otherwise.
E.g., on one machine, I have:

$ cat /etc/ifconfig.tlp0
inet alias 10.0.0.1/16 broadcast 10.0.255.255
inet alias 10.1.0.1/16 broadcast 10.1.255.255
inet alias 10.2.0.1/16 broadcast 10.2.255.255
inet6 alias 3ffe:1ce1:0:fe70::1 prefixlen 64
$