Bridge Not Forwarding ARP

[Joseph Ward]

I had this exact issue while virtualbox had a guest network adapter
bridged to the external interface that the FreeBDS bridge0 interface was
bridged to.  If I shutdown the VMs, ARP magically started working
bidirectionally, and after restarting the VMs it failed again.

My fix was eventually to just have 2 external NICs; one exclusively for
the virtualbox systems.  I have no idea if you have a virtualbox guest
present, but if so that was my fix. 

The issue occurred on both igb and re NICs.

-Joseph

On 2019-07-08 12:13, Dan Lists wrote:
> I have a server running FreeBSD 11.2 that I am wanting to use as a bridged
> firewall.  I have it set up and it mostly works.   The problem is that ARP
> replies are not being forwarded from the outside interface to the inside
> interface.   It appears to be working in the other direction.  I see the
> ARP request go out on the outside interface and the reply arrives back at
> the outside interface.   The ARP reply is never getting to the bridge or to
> the inside interface.
>
> The firewall server and the device behind it are in ESX.   I think I've
> worked all the ESX issues out.  When I manually add an ARP entry everything
> works.   I've done this before with a physical server running FreeBSD 8.4
> and it works as expected.   The differences are physical vs virtual, and
> 8.4 vs 11.2.
>
> I'm at a loss as to why it is not working.   I've searched the web and
> found noting.  If anyone could offer suggestions on how to fix this or
> begin to debug it I would greatly appreciate it.
>
> Thanks,
>
> Dan
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