Open Stack

All,

I’ve just upgraded our cloud from Havana to Juno.

I’ve succeeded in configuring Neutron with a flat, external network and individual tenants can attach to it via a virtual router and floating address, using GRE tunnels.  However, I also need to configure a simple flat network for a given tenant that maps directly to our campus network (i.e. WAN).

I’m having problems getting this configured correctly.  Neutron is configured entirely on its own node, with multiple interfaces: eth0 is attached to our campus network and serves as the management interface, br-ex (eth2) is attached to our campus backbone and is used to create the “external" flat network, br-data (eth1) is attached to the cloud’s data network. Compute nodes are configured with a single interface br-data (eth0).

Now to create a simple flat network:

*  can I share the br-ex interface or do I need to use a separate physical interface on the network node? Neutron complains loudly when I try to do this, so I suspect the answer is an emphatic NO.
*  is a GRE tunnel still used for a simple flat network between the compute nodes and the network node?
*  when I bring up a separate external interface (call this br-ex2) and try to create the simple flat network using this physical interface, then when I try to boot an instance it fails with a “No available host” found”, with errors also in the nova-conductor log regarding vif interface mapping problems.

I had this working in Havana using VLAN networks, but can’t seem to get things working with GRE tunnels. 

Any tips/pointers would be appreciated
—
Ross Lillie, Motorola Solutions
CTO, SST, Applications & Services Research