The Quantum project provides a tenant-facing API for defining network connectivity and addressing in the cloud. It supports different network technologies and components. Key use cases include single flat networks, multiple flat networks, mixed private and flat networks, provider routers with private networks, and per-tenant routers with private networks.

1. What is Quantum?

2. The Quantum project was created to provide a rich and tenant-facing API
for defining network connectivity and addressing in the cloud.
Network
Subnet
Port

3. Flexibility to Choose Different Network Technologies
Open vSwitch
Cisco
Linux Bridge
Nicira NVP
Ryu
NEC OpenFlow

5. Different Components
• quantum-server
• plugin agent (quantum-*-agent)
• dhcp agent (quantum-dhcp-agent)
• l3 agent (quantum-l3-agent)

6. Use Case: Single Flat Network

7. • This is a "shared" network, meaning it is
visible to all tenants via the Quantum API.
Tenant VMs have a single NIC, and receive a
fixed IP address from the subnet(s) associated
with that network. This essentially maps to
the FlatManager and FlatDHCPManager
models provided by Nova. Floating IPs are not
supported.

8. Use Case: Multiple Flat Network

9. • This use case is very similar to the above
Single Flat Network use case, except that
tenants see multiple shared networks

10. Use Case: Mixed Flat and Private Network

11. in which tenants also optionally have access to
private per-tenant networks. In addition to seeing
one or more shared networks via the quantum API,
tenants can create additional networks that are
only visible to users of that tenant. When creating
VMs, those VMs can have NICs on any of the shared
networks and/or any of the private networks
belonging to the tenant. This enables the creation
of "multi-tier" topologies using VMs with multiple
NICs. It also supports a model where a VM acting as
a gateway can provide services such as routing, NAT,
or load balancing.

12. Provider Router with Private Networks

13. This use provides each tenant with one or more
private networks, which connect to the outside
world via a Quantum router. The case where
each tenant gets exactly one network in this
form maps to the same logical topology as the
VlanManager in Nova. Using the Quantum API,
the tenant would only see a network for each
private network assigned to that tenant. The
router object in the API is created and owned by
the cloud admin.

14. Per-tenant Routers with Private
Networks

15. A more advanced router scenario in which each tenant
gets at least one router, and potentially has access to the
Quantum API to create additional routers. The tenant can
create their own networks, potentially unlinking those
networks to a router. This model enables tenant-defined
multi-tier applications, with each tier being a separate
network behind the router. Since there are multiple
routers, tenant subnets can be overlapping without
conflicting, since access to external networks all happens
via SNAT or Floating IPs. Each router uplink and floating IP
is allocated from the external network subnet.

17. • 3 Servers
Server 1 = > running network controller and nova-compute
Server 2 = > running nova-compute, Cinder, rabbit-mq, mysql, keystone, glance, swift
Server 3 = > running nova-compute
• All servers are having 4 lan card, eth0 is connected to public switch and rest are connected to
private switch.
eth3 of Server 1 is also connected to public switch for br-ex. all node eth2 is for br-int
• 10.10.x.x is for public access
• 172.24.0.x is for private network
• 172.24.x.x is reserved for tenant Network

18. Network Node Setup
• vi /etc/network/interfaces
auto eth0
iface eth0 inet static
address 10.10.1.2
netmask 255.255.255.0
gateway 10.10.1.254
dns-nameservers 10.10.2.2
###### VMs Networks with OVS in tunnel mode
auto eth1
iface eth1 inet manual
up ifconfig $IFACE 0.0.0.0 up
up ip link set $IFACE promisc on
down ip link set $IFACE promisc off
down ifconfig $IFACE down
############ Public Bridge
auto eth3
iface eth3 inet manual
up ifconfig $IFACE 0.0.0.0 up
up ip link set $IFACE promisc on
down ip link set $IFACE promisc off
down ifconfig $IFACE down

19. #virsh net-destroy default
#virsh net-undefine default
#vi /etc/libvirt/libvirtd.conf
listen_tls = 0
listen_tcp = 1
auth_tcp = “none”
#vi /etc/init/libvirt-bin.conf
env libvirtd_opts=”-d -l”
# vi /etc/default/libvirt-bin
libvirtd_opts=”-d -l”
# service libvirt-bin restart
#vi /etc/default/openvswitch-switch
BRCOMPAT=yes
#aptitude purge ebtables
#apt-get install -y openvswitch-datapath-source
#apt-get install -y quantum-server quantum-plugin-openvswitch
#module-assistant auto-install openvswitch-datapath
#service openvswitch-switch start
#lsmod |grep br
#rmmod bridge
#service openvswitch-switch restart
#service openvswitch-controller restart
#lsmod |grep br
#init 6

20. Network setup for Compute Nodes
• #vi /etc/network/interfaces
## Management Network
auto eth0
iface eth0 inet static
address 10.10.1.1
netmask 255.255.255.0
gateway 10.10.1.254
dns-nameservers 10.10.2.2
## VMs Networks with OVS in tunnel mode
auto eth1
iface eth1 inet manual
up ifconfig $IFACE 0.0.0.0 up
up ip link set $IFACE promisc on
down ip link set $IFACE promisc off
down ifconfig $IFACE down

21. How to create Quantum Network
• Internal Network
• Internal Subnet
• Router
• External Network
• External Subnet
• Floating IP

22. Internal Network
# quantum net-create pvt_net1 --tenant_id
6415b015581c4506a46e97170395a598 --
provider:network_type gre --
provider:segmentation_id 1 --shared True
# quantum net-create pvt_net2 --tenant_id
6415b015581c4506a46e97170395a598 --
provider:network_type gre --
provider:segmentation_id 2 --shared True

23. Internal Subnet
• quantum subnet-create --tenant_id
6415b015581c4506a46e97170395a598 --
ip_version 4 c92921e3-64a7-468c-8b96-
e3acdfc469c0 172.24.1.0/24
• quantum subnet-create --tenant_id
6415b015581c4506a46e97170395a598 --
ip_version 4 1b61152f-f611-4817-9980-
79636392ab8b 172.24.2.0/24

24. Router
# quantum router-create --tenant_id
566b4109018540c3b41d8b7f3acc96f2
oss_router
# quantum router-interface-add a08467a3-
6688-4810-8fee-86ad695cfd43 8bf56636-fe18-
4386-8018-de86cfa4cec8

25. External Router
# quantum net-create ext_net -- --
router:external=True
# quantum subnet-create --ip_version 4 --
allocation-pool
start=10.83.192.11,end=10.83.192.125 --
gateway 10.83.192.254 6377fc4c-9d0c-4690-
976b-09a9ddac9ef6 10.83.192.0/24 -- --
enable_dhcp=False

26. FLOATING IP
# quantum floatingip-create ext_net
# nova list
# quantum port-list -- --device_id 1cdc671d-
a296-4476-9a75-f9ca1d92fd26
# quantum floatingip-associate $FLOATING_ID
$PORT_ID
# quantum floatingip-show $FLOATING_ID