Hi! I need your help!

Strange things happen in my Mitaka DVR setup:

My external bridge (Br-ex) has a port connected to the external network.

I can ping br-ex from external network.

I can ping br-ex from internal network.

BUT my br-ex doesn't forward packets from internal network to the external network !

For example:

[from internal network] ----> pinging br-ex is ok

[from internal network] ----> pinging 8.8.8.8 shows "Destination Host Unreachable"

What's happening?