[ovs-discuss] Behavior when ping "internal" bridge interface ip with dpdk port attached

Du, Fan fan.du at intel.com
Wed Aug 26 14:27:52 UTC 2015

After creating a user space ovs bridge, and assign an valid ip address
after the "internal" bridge name, then add a physical interface, e.g. 
ens806f1 to the bridge. Ping the internal bridge ip address from the 
other host will work ok.

But once I prevent all the packets reaching ens806f1 by iptable rules,
Ping from the other host will not work. So my understanding is kernel
network stack responds to the ARP request, in which case bypass ovs user
space bridge.
iptables -A INPUT -i ens806f1 -j DROP
iptables -A FORWARD -i ens806f1 -j DROP

But when attaching a dpdk type port(instead of the physical interface
like ens806f1) to the bridge,I can tcpdump ARP_REPLY from the dummy
mirroring port, but the ARP_REPLY packet didn't reach from the other host.

So I'm puzzled, in scenario of dpdk port attached:
a. which part of code build the ARP_REPLY packet?
b. why the arp reply packet didn't hit on wire after setting arp with
    normal action flow?

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