Deploying IPv6 on OpenStack

1. Deploying IPv6
on OpenStack
Tung Nguyen Thanh - VCCloud
Oct 7 - 2017

2. Agenda
● IPv6 Overview
● IPv6 address management
● IPv6 deployments options and consideration
points in OpenStack
● Deploying and Troubleshooting

3. IPv4: Running Out of Addresses
- Short term solutions included:
+ NAT (Network Address Translation)
+ Private address space
+ CIDR (Classless Inter-Domain Routing)
- Long-term solution: IPv6

4. Introducing IPv6
● Not a “new” protocol.
● Developed mid to late
1990s.
● Much learned from IPv4.
● 128-bit address space,
written in hexadecimal.
● This gives us 340
undecillion addresses!

5. IPv6 Address Types

6. Global Unicast Address

7. IPv6 Address Allocation

8. IPv6 Overview
● IPv6 is not just about more addresses:
○ Stateless autoconfiguration
○ End-to-end reachability without private addresses
and NAT
○ Better support for mobility
○ Peer-to-peer networking easier to create and
maintain, and services such as VoIP and Quality of
Service (QoS) become more robust.
○ Security
○ Routing

9. IPv5 ?
IPv10 ?
Is ‘IPv6’ faster ?

10. IPv6 address configuration modes
Three configuration modes:
● SLAAC
● DHCPv6 stateless
● DHCPv6stateful

11. The configuration mode is
determined based on RA flag:
● M (Managed) => 0
(RA/DHCPv6 stateless), 1
(DHCPv6 stateful
● O (Other) => 0 (SLAAC), 1
(use DHCPv6)

12. SLAAC (Stateless Address Autoconfiguration)
● IPv6 address of a client is configured based on RA (Router
advertisement)
● Gateway is also configured.
● Optionally, DNS information(if RFC6106), MTU and so on can be
configured.
● Only /64 prefix is used

13. DHCP v6 Stateless
● IPv6 address is configured based on RA
● Other information is retrieved via DHCPv6
● Looks used most commonly
● Only way to distribute DNS info before RFC6106

14. DHCP v6 Stateful
● All information is configured based on DHCPv6
● There is information that GW is not configured properly.

15. Deployment IPv6

16. Dual Stack IPv4 IPv6

17. NAT64/DNS64

18. Network Tunnel

19. IPv6 on Openstack
Two attributes related to IPv6 address configuration:
- Ipv6_address_mode: Control of how addressing is handled by
OpenStack
- Ipv6_ra_mode: Control of router advertisements for a subnet
There are constraints between two modes
- OpenStacknetworking guide
- https://docs.openstack.org/ocata/networking-guide/config-ipv6
.html
- https://access.redhat.com/documentation/en-us/red_hat_opens
tack_platform/9/html/networking_guide/sec-ipv6

20. ● IPv6 address mode: Specifies how IPv6 address is generated and
assigned, IPAM is mainly involved in it and Also controls if the
reference DHCP implementation serves
● “Slaac”: Neutron generates a port address based on MAC address
(EUI-64)
● “Dhcpv6-stateless”:
- Neutron generates a port address based on MAC address (EUI-64)
- Neutron provides DHCP options for port
● “Dhcpv6-stateful”
- Any address can be configured
- Perhaps non-/64 prefix can be used
● Not Specified (N/S)
- (Backward compatibility)
- Any static address can be configured.

21. ● IPv6 RA mode: Specifies how neutron router sends RA
● "slaac"
● "dhcpv6-stateles"
● "dhcpv6-stateful"
- Neutron setup radvd on a router and provides RA
- RA flags are set accordingly
● Not Specified (N/S)
- Neutron does nothing.
- radvd on a router is not setup

22. The behavior of the neutron router for IPv6
- Internal router ports, that act as default
gateway ports for a network, will share
a common port for all IPv6 subnets
associated with the network.
- Neutron tenant networks that are
assigned Global Unicast Address
(GUA) prefixes and addresses don’t
require NAT on the neutron router
external gateway port to access the
outside world
- GUA IPv6 subnet prefix is not
necessarily needed for the neutron
external network. By default, a IPv6
LLA associated with the external
gateway port can be used for routing
purposes.

23. Vccloud Ipv6

24. Dual Stack VM

25. Changelog on images (glance)
RHEL / CentOS / Oracle Linux
Edit the file /etc/sysconfig/network and add the following parameter:
NETWORKING_IPV6=yes
Edit the file /etc/sysconfig/network-scripts/ifcfg-eth0 and add the following
two parameters:
IPV6INIT=yes
DHCPV6C=yes

26. Changelog on images (glance)
Ubuntu
Edit the file /etc/dhcp/dhclient6.conf and add the following line:
timeout 10;
Edit the network configuration for the eth0 interface with the following
configuration:
Edit the file /etc/network/interfaces
iface eth0 inet6 dhcp

27. Changelog on images (glance)
Windows
netsh interface ipv6 set interface 15 routerdiscovery=disabled
netsh interface ipv6 set interface 15 managedaddress=enabled
netsh interface ipv6 set interface 15 otherstateful=enabled
https://support.microsoft.com/en-us/help/961433/how-to-configure-a-windo
ws-vista-client-to-obtain-an-ipv6-dhcp-address

28. Troubleshooting

35. Q&A

36. Thank you