[ovs-discuss] [ovs-dev] how a trunk port treats untagged packets

[Ben Pfaff]

On Sat, Dec 24, 2016 at 11:50:00AM +0800, 贺斌 wrote:
> hello all,
>    I'm a ovs beginer. Recently, I test on ovs trunk port:
>    1. I created a ovs bridge named br0, and then add two trunk ports on it,  named if0, if1. And the trunk is the same, 44,55,66.
>    2. Then I put intreface if0 to Linux name space ns0, and if1 to ns1.
>    3. Associate a ip 110.0.0.2/24 on if0 in ns0 and 110.0.0.2/24 on if1 in ns1.
>    4. The I execute 'ping 110.0.0.3' from ns0, But I can't get any packet captured on default intterface br0 or if1 in ns1 using 'tcpdump'. But when I use comman 'ovs-ofctl dump-flows br0',  I find that every time after I excute ping commands, there is an increase of 3 for 'n_packets' in the flow. I guest it's arp packets. But I can't capture it from any where.
> 
> 
>  I'm sure all the interface is up,  and  the route table is corret.
>  
>  So, I wonder that, when an untagged packet passed to the trunk port directly, how the ovs brigde treat it? Drop it directly or add a default VLAN id then forwarding it?

Untagged packets are in VLAN 0.