IP Aliasing Question

[Andrew Kilpatrick]

Hey,

What I'm trying to do involves FreeBSD and IP aliases. Hopefully someone has 
some ideas. Here's the general idea of what I'm trying to do:

I've got vr0, which is assigned to some IP address... let's say: 192.168.1.90 
with a subnet mask of 255.255.255.0. This is all fine, and everything works.

I'm implementing a protcol called ArtNet (which I didn't design) which uses 
10.x.x.x network for controlling lighting. It's all UDP, and uses broadcast 
packets to 10.255.255.255. IP addresses of hosts are determined by a sort of 
shitty algorithm based on the MAC address, and can appear anywhere in the 
class A. This allows: a) IPv4 (yes, I know IPv6 would be better) and b) 
autoconfiguration without the need for a DHCP server. I didn't make it up, 
I'm just trying to make my stuff work with it.

So, here's the deal.... I want to add 2 aliases to vr0 so that I can run 2 
ArtNet services on the same machine. So, the aliases would look something 
like this:

10.0.38.237 netmask 255.0.0.0
10.255.38.237 netmask 255.0.0.0

Adding the first one like this works: ipconfig vr0 inet 10.0.38.237 netmask 
255.0.0.0 alias

However, adding the second fails, I'm assuming because the netmasks overlap. I 
can understand why this is so, but for my application I actually want this. 
Because programs listening on both addresses both need to receive broadcast 
packets sent to 10.255.255.255.

So, how can this be done? Adding a second NIC is not an option.


Cheers,

Andrew