Multiple Interfaces

Bob bob at starblanket.ca
Thu Jul 31 10:01:06 PDT 2003


Greets 

> I have two interfaces and the following info in rc.conf.  The 
> first one is
> setup properly but the second one never gets configured.
 
I just went through this process myself.

The word I have is that FreeBSD cannot run two NICs on
the same subnet, which is what your included config shows.
So try as you may it will not work. I also tested 4.7, 5.0 
and 5.1 with similar results. 

Here is a snippet of an email I received on this topic:

Begin

Well, as long as I can tell, one can't have 2 ifaces on the same subnet 
on FreeBSD. This seems to be regarded as a feature by the guys who have 
written the code. "It's arguable that it should be done any other way, 
since it will put questions like  what interface will be used for 
outgoing segments to the subnet ? etc. which will require to manually  
assign the arp table as log as you have the rest of the nodes of the 
subnet connected throu some kind of switches or to still have all 
outgoing connections throu a preferred interface which will require a 
SRC (IP+MAC) addresses of the other interface and will unnecessary 
complicated the hole thing". So the result will be a gain in the speed 
of incoming segments but more load on the system.

END

>What am I missing?

All you are missing is the fact FreeBSD cannot handle
two NICs the same subnet. OpenBSD does, NetBSD does and Linux does.

Regards

Bob D



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