Problems with two interfaces on the same subnet?

[Eggert, Lars]

Hi,

On Feb 12, 2013, at 9:32, Ivan Voras <ivoras at freebsd.org> wrote:
> I have a machine with two interfaces, igb2 and igb3 on the same subnet
> but with different IP addresses, e.g. igb2 has 192.168.1.221, igb3 has
> 192.168.1.222. Firstly, is there anything which would preclude this from
> working? As I see it, these are two different MAC addresses and to the
> outside world should look as two different hosts, right?

depends on what you mean by "work". There will only be one default route out of the box.

> * With both NICs connected to different switches, everything appears to
> work, BUT, if igb2 cable is disconnected, pings to igb3 simply stop,
> even though its cable *is* still connected.

This sounds like your default route is going via igb2.

You can make this work with ipfw rules (and I guess also setfib, although I have not tried that.)

Lars