On Tue, Feb 04, 2003 at 11:35:29PM -0600, Mike McClure wrote:

> So, one would expect a workstation on network A to be able to connect to port 9999
> on a given address and get the SSH daemon on the OBSD system, correct?

Not on a bridge, if the destination mac address of the incoming frame is
doesn't match one of the bridge's own interfaces.

192.168.2.10 sends the ethernet frame to the mac address of the default
gateway (add -e to the tcpdump options to see the mac addresses), and
the bridge doesn't care whether the destination IP address has changed
to one of its own IP addresses during translation. It operates only on
mac addresses.

So, the destination mac address is not its own, and the frame gets sent
out through the interface where the destination is reachable (dc0). The
frame never gets forwarded to the firewall's own TCP/IP stack at all.

I doubt this exact same setup has worked with 3.1, as there were no
bridge changes relevant to this. Possibly the gateway used to forward
the packets back to 192.168.2.250 before, and now doesn't. But the
bridge code never looked at the destination IP address after translation
to direct the packet to the stack instead of forwarding the frame.

You can try using 'fastroute' or 'route-to' to manually route the
packets to the stack from pf (so the bridge will not get the packet back
from pf, and pf does the forwarding).

Daniel

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