[ovs-dev] Ports down on OVS DPDK and traffic fails

[Nadathur, Sundar]

Summary: I am trying to bring up two tap devices on a ovs-dpdk switch, but both ports are down and traffic doesn't work, even after adding a VM. Would appreciate some help.

Compiled OVS 2.7.0 (from the tar ball) with DPDK 17.02 as follows:
./configure --with-dpdk=$DPDK_BUILD CFLAGS="-g -O2 -msse4.2"
make
make install

During the bring up, I initialized as follows:
ovs-vsctl --no-wait set Open_vSwitch . other_config:dpdk-init=true
Created the bridge and ports with these commands:
ovs-vsctl add-br br0 -- set bridge br0 datapath_type=netdev
ip tuntap add mode tap vi1
ip tuntap add mode tap vi2
ip addr set ... dev v1 # same for vi2
ovs-vsctl add-port br0 vi1 -- set Interface vi1 type=dpdkvhostuser #same for vi2

But both ports show as NO-CARRIER even after 'ip addr .. up':
# ip addr show vi1
22: vi1: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN qlen 500
    link/ether 3a:19:09:52:14:50 brd ff:ff:ff:ff:ff:ff
    inet 200.1.1.1/24 scope global vi1
       valid_lft forever preferred_lft forever

I can ping the IP addresses of vi1 and vi2, but 'ping 200.1.1.1 -I vi2' fails. ARP doesn't get resolved, wireshark (tshark) shows no traffic on the switch, and 'ovs-ofctl dump-flows' shows that the stats are not going up.

First, I would expect at least the ARP packets to go through and the stats to go up (even though the ping won't succeed because there is nothing on the second switch port vi2 to respond.) Why is that not working?

Second,  I then brought up a VM connecting to vi1. But, vi1 still shows as NO-CARRIER, and traffic from VM doesn't work. What could be going wrong here? (I can add more details as needed.)

Thanks,
Sundar


Regards,
Sundar