NetBSD and IP host models

[Sad Clouds <cryintothebluesky%gmail.com@localhost>]

Hi, I have some niche use cases that need support for "strong end
system model" which can perform symmetric IP routing.

As far as I can see, there are some obstacles with NetBSD:

1. NetBSD uses "weak end system model", so a multihomed host is prone
to ARP flux when multiple IP addresses are configured on the same
subnet and on the same host.

2. Sending IP packets from eth0 to eth1 on the same host, results in a
fast forward path, where packets are forwarded internally within the
kernel, without leaving eth0 and traversing the network, which is not
what I need.

On Solaris 11.3 I can easily switch IP host models with this command:

# ipadm set-prop -p hostmodel=strong ipv4

this enables symmetric routing and forces IP packets to traverse the
network, even when sent between network interfaces on the same host.

I'm not sure I can achieve anything similar on NetBSD and don't see
any relevant sysctl settings for this. Any suggestions?

Thanks.