How fg interface work?

asked 2018-08-01 11:07:07 -0500

anonymous user



I have a simple question about openstack. I have a VM with floating ip A. When I run: ip netns exec fip-d04467c4-6ab9-44f8-ac98-61837c3e8f4f ping vm_fip_address That's right, there is no problem in the connection between net ns qrouter and net ns fip. Net ns fip has a fg interface, and it is a member of int-br. Net ns have default gw, this is a dummy interface on the host machine, and this dummy interface is member br-ext-X. Br-extX and int-br have a patch-link. (

What is the interface for fip? When I start ip netns exec fip_ns_name ip -d a I notice that the type of interface is openwswitch (I'm using the neutron plugin ml2). Now I have a problem with ARP, between the fg interface and the fip net ns gw(dummy). This is not a routing problem, it's a problem with ARP.

This is simplification for vagrant users: {code}

- * - mode: ruby ​​- * -

vi: set ft = ruby:

Vagrant.configure ("2") do | config | = "centos / 7" "private_network", ip: ""

config.vm.provision "shell", inline: << - SHELL

modprobe dummy

yum install -y epel-release tmux net-tools tcpdump kernel yum install -y openvswitch systemctl start openvswitch.service

ip link add Type of dummy ip addr add dev A ip link set A up ip netns add NS ip netns exec NS ip link add B type of dummy ip netns exec NS ip addr add dev B ip netns exec NS ip link set B up ip netns exec ip ip link set lo up ovs-vsctl add-br BR ovs-vsctl add-port BR A-set Interface Type A = internal ip netns exec NS ovs-vsctl add-port BR B-set Interface type B = internal ip r add dev BR ip netns exec NS ip r add dev B ip netns exec NS ip r add dev B ip netns exec NS ip r add the default value via dev B

SHELL end {code}

In tcpdump, I have arp requests when i ping the fg interface from the host machine (without response) ip r show that I have a good route to the openswitch's bridge

ovs-dpctl dump streams | grep "my src interface mac" recirc_id (0), in_port (20), eth (src = my src interface mac, dst = ff: ff: ff: ff: ff: ff), eth_type (0x0806), arp (sip = src ip, tip = fg ip , op = 1 / 0xff), packages: 75, bytes: 3150, used: 0.213s, the action: 19 but not an arp request for tcpdump in fip net ns.

ip netns exec NS tcpdump -vvvv -i any -e <empty>

How to debug this problem?

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