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Problems configuring multiple external networks with Neutron?

asked 2015-03-18 15:20:01 -0500

daniel-wilson gravatar image

Hello, I have configured multiple external networks with Neutron and things are ALMOST working. I have three flat external networks and each has router with private networks/subnets. I create an instance with all three networks and then assign floatingip addresses to all. The network that is in eth0 will work as expected with floatingip address, no matter which network it is. The other networks on eth1 and eth2 do not work as expected.

I am able to receive ping (ICMP) packets on eth1 and eth2 interfaces on my instances. However, the eth1 and eth2 interfaces do not reply to the ping. Is there some trick to make eth1 and eth2 reply to ping requests? Any suggestions on further debugging/troubleshooting?

Thanks!

This block shows a tcpdump on eth1 that has an ipaddress of 10.1.10.10. The ping request comes in but is ignored.

ubuntu@networktestall:~$ sudo tcpdump -i eth1 -nvvvS
sudo: unable to resolve host networktestall
tcpdump: listening on eth1, link-type EN10MB (Ethernet), capture size 65535 bytes
19:12:31.815336 IP (tos 0x0, ttl 63, id 0, offset 0, flags [DF], proto ICMP (1), length 84)
    10.0.1.9 > 10.1.10.10: ICMP echo request, id 13010, seq 1, length 64
19:12:32.814930 IP (tos 0x0, ttl 63, id 0, offset 0, flags [DF], proto ICMP (1), length 84)
    10.0.1.9 > 10.1.10.10: ICMP echo request, id 13010, seq 2, length 64
19:12:33.814933 IP (tos 0x0, ttl 63, id 0, offset 0, flags [DF], proto ICMP (1), length 84)
    10.0.1.9 > 10.1.10.10: ICMP echo request, id 13010, seq 3, length 64
19:12:34.814919 IP (tos 0x0, ttl 63, id 0, offset 0, flags [DF], proto ICMP (1), length 84)
    10.0.1.9 > 10.1.10.10: ICMP echo request, id 13010, seq 4, length 64
19:12:35.815741 IP (tos 0x0, ttl 63, id 0, offset 0, flags [DF], proto ICMP (1), length 84)
    10.0.1.9 > 10.1.10.10: ICMP echo request, id 13010, seq 5, length 64
19:12:36.814915 IP (tos 0x0, ttl 63, id 0, offset 0, flags [DF], proto ICMP (1), length 84)
    10.0.1.9 > 10.1.10.10: ICMP echo request, id 13010, seq 6, length 64
19:12:36.828969 ARP, Ethernet (len 6), IPv4 (len 4), Request who-has 10.1.10.10 tell 10.1.10.1, length 28
19:12:36.828982 ARP, Ethernet (len 6), IPv4 (len 4), Reply 10.1.10.10 is-at fa:16:3e:d2:32:6e, length 28
19:12:37.814863 IP (tos 0x0, ttl 63, id 0, offset 0, flags [DF], proto ICMP (1), length 84)
    10.0.1.9 > 10.1.10.10: ICMP echo request, id 13010, seq 7, length 64
^C
9 packets captured
9 packets received by filter
0 packets dropped by kernel
ubuntu@networktestall:~$ ifconfig
eth0      Link encap:Ethernet  HWaddr ...
(more)
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This may be a stupid question but what is the default gateway on the guest OS? You can't have 3 gateways on an OS at the same time without modifiying iptables and specifying the routes for every eth!

capsali gravatar imagecapsali ( 2015-10-05 04:16:53 -0500 )edit

Thanks everyone. We have since moved on from this configuration and went with a different network setup. I am pretty sure the answer to this one was to modify the iptables to specify the routes for every interface.

daniel-wilson gravatar imagedaniel-wilson ( 2015-10-05 11:12:50 -0500 )edit

2 answers

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answered 2015-10-04 21:49:53 -0500

penghon gravatar image

I assume that you are using openvswitch? What is the output of your ovs-vsctl show?

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answered 2015-10-05 07:29:39 -0500

dbaxps gravatar image

updated 2015-10-05 07:32:09 -0500

Follow http://blog.oddbit.com/2014/05/28/mul... on Network Node.
The key commands per link above

neutron net-create external1 -- --router:external=true \
  --provider:network_type=flat \
  --provider:physical_network=physnet1 
neutron subnet-create --disable-dhcp external1 10.1.0.0/24
neutron net-create external2 -- --router:external=true \
  --provider:network_type=flat \
  --provider:physical_network=physnet2
neutron subnet-create --disable-dhcp external2 10.2.0.0/24

Keep following Larsks

This assumes that eth1 is connected to a network using 10.1.0.0/24 and eth2 is connected to a network using 10.2.0.0/24, and that each network has a gateway sitting at the corresponding .1 address.

As tenant demo create router1,router2, demo_net1,demo_net2
For router(X) create gateway to external(X) and interface to demo_net(X)

You are supposed to see qg-xxxxxxxx interfaces for both qrouter-namespaces attached to br-int
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Asked: 2015-03-18 15:20:01 -0500

Seen: 213 times

Last updated: Oct 05 '15