kern/41597: Load balancing (ECMP) on NetSD 3.1

[wajid.mohammed%wipro.com@localhost]

>Number:         41597
>Category:       kern
>Synopsis:       Load balancing (ECMP) on NetSD 3.1
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    kern-bug-people
>State:          open
>Class:          support
>Submitter-Id:   net
>Arrival-Date:   Mon Jun 15 07:40:00 +0000 2009
>Originator:     Wajid Mohammed
>Release:        NetBSD 3.1
>Organization:
Wipro
>Environment:
NetBSD  3.1 NetBSD 3.1 (GENERIC) #0: Mon Jan 15 12:50:38 PST 2007  
bob@rachel:/home/bob/NetBSD/objs/sys/arch/i386/compile/GENERIC i386
-bash-3.2#

>Description:
I am trying to achieve load balancing (Equal Cost Multiple Path) on NetBSD 3.1, 
but I am unable to install more than one route on the kernel for the same 
destination.

For Ex:

I have two active interfaces on my box having IP addresses 1.1.1.2/24 and 
30.0.0.3/24.

bash-3.2# route add -net 21.21.21.0 -netmask 255.255.255.0 1.1.1.2
add net 21.21.21.0: gateway 1.1.1.2
bash-3.2#
bash-3.2#
bash-3.2# route add -net 21.21.21.0 -netmask 255.255.255.0 30.0.0.3
writing to routing socket: File exists
add net 21.21.21.0: gateway 30.0.0.3: File exists
bash-3.2#

Does NetBSD 3.1 has support for Load balancing?
How can I configure Load Balancing on NetBSD in case it has this support?
>How-To-Repeat:

>Fix: