Running VXLAN over an IPv6-only Underlay Network

While RFC 7348 specifies VXLAN transport over IPv4 and IPv6, very few vendors implemented VXLAN over IPv6. That unfortunate situation is slowly changing with the advent of IPv6-only data centers (and related customer pressure), leading to several implementations of VXLAN over IPv6. Does your device support it? You’ll find out in this lab exercise.

Device Requirements

You can use any device supported by the netlab OSPF and VLAN configuration modules. The device should support VXLAN with static ingress replication over IPv6 transport.

Start the Lab

Assuming you already set up your lab infrastructure:

• Change directory to vxlan/6-ipv6
• Execute netlab up
• Log into lab devices with netlab connect and verify that the IP addresses and the OSPFv3 routing are properly configured.

Existing Device Configuration

• The switches in your lab (S1, S2, and S3) are preconfigured with red VLAN using VLAN tag 100.
• IPv4 addresses are configured on Linux hosts and switch loopback interfaces¹. IPv6 addresses are configured on switch loopback interfaces and interswitch links (details).
• The switches run OSPFv3 in area 0 (details).

Configuration Tasks

Using the commands you mastered in the Extend a Single VLAN Segment with VXLAN lab exercise, extend the red VLAN between all three switches. You’ll also have to:

• Configure IPv6 transport for VXLAN. That’s often configured on the VXLAN interface, and the parameter is sometimes called vxlan encapsulation.
• Use IPv6 peer VTEP addresses in the VXLAN ingress replication lists.

Verification and Troubleshooting

H1, H2, and H3 should be able to ping each other. Use commands similar to netlab connect h1 ping h2 to check that.

Use the troubleshooting hints from the Extend a Single VLAN Segment with VXLAN lab exercise if you can’t establish end-to-end connectivity.

You should also check that the ingress replication lists use IPv6 addresses with commands similar to show vxlan flood vtep

Per-VLAN VXLAN ingress replication lists on S1 running Arista EOS

s1#show vxlan flood vtep
          VXLAN Flood VTEP Table
--------------------------------------------------------------------------------

VLANS                            Ip Address
-----------------------------   ------------------------------------------------
100                             2001:db8:cafe:2::1 2001:db8:cafe:3::1

Cheating

• Shut down your lab with the netlab down command
• Start the lab from the solution.yml topology with the netlab up solution.yml command
• Explore the device configurations

Reference Information

Lab Wiring

Origin Device	Origin Port	Destination Device	Destination Port
s1	Ethernet1	s2	Ethernet1
s2	Ethernet2	s3	Ethernet1
s3	Ethernet2	s1	Ethernet2
s1	Ethernet3	h1	eth1
s2	Ethernet3	h2	eth1
s3	Ethernet3	h3	eth1

Lab Addressing

Node/Interface	IPv4 Address	IPv6 Address	Description
s1	10.0.0.1/32	2001:db8:cafe:1::1/64	Loopback
Ethernet1		2001:db8:101::1/64	s1 -> s2
Ethernet2		2001:db8:101:2::1/64	s1 -> s3
s2	10.0.0.2/32	2001:db8:cafe:2::1/64	Loopback
Ethernet1		2001:db8:101::2/64	s2 -> s1
Ethernet2		2001:db8:101:1::1/64	s2 -> s3
s3	10.0.0.3/32	2001:db8:cafe:3::1/64	Loopback
Ethernet1		2001:db8:101:1::2/64	s3 -> s2
Ethernet2		2001:db8:101:2::2/64	s3 -> s1
h1
eth1	172.16.0.4/24		h1 -> [s1,h2,s2,h3,s3]
h2
eth1	172.16.0.5/24		h2 -> [h1,s1,s2,h3,s3]
h3
eth1	172.16.0.6/24		h3 -> [h1,s1,h2,s2,s3]

OSPF Routing (Area 0)

Router	OSPFv3 Router Identifier
s1	10.0.0.1
s2	10.0.0.2
s3	10.0.0.3

Router	Interface	IPv6 Address	Neighbor(s)
s1	Loopback	2001:db8:cafe:1::1/64
	Ethernet1	2001:db8:101::1/64	s2
	Ethernet2	2001:db8:101:2::1/64	s3
s2	Loopback	2001:db8:cafe:2::1/64
	Ethernet1	2001:db8:101::2/64	s1
	Ethernet2	2001:db8:101:1::1/64	s3
s3	Loopback	2001:db8:cafe:3::1/64
	Ethernet1	2001:db8:101:1::2/64	s2
	Ethernet2	2001:db8:101:2::2/64	s1