Re: fib selection and persistence using ipfw

From: Rozhuk Ivan <rozhuk.im_at_gmail.com>
Date: Tue, 09 Dec 2025 15:26:36 UTC
On Mon, 8 Dec 2025 08:38:22 -0500
Michael Butler <imb@protected-networks.net> wrote:

> > Do not forget set fib to network interface like it done in examlpe.
> > In my case if same IP+mask set on more than one net if - only last
> > one will process packets to sockets.  
> 
> Interface FIBs only work when the connection stays on the same
> machine.


https://man.freebsd.org/cgi/man.cgi?ifconfig
       fib fib_number
	       Specify	interface  FIB.	  A  FIB fib_number is assigned	to all
	       frames or packets received on that interface.  The FIB  is  not
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^!!!
	       inherited, e.g.,	vlans or other sub-interfaces will use the de-
	       fault  FIB (0) irrespective of the parent interface's FIB.  The
	       kernel needs to be tuned	to support more	than the  default  FIB
	       using  the  ROUTETABLES	kernel	configuration  option,	or the
	       net.fibs	tunable.