Setting up an FMIPv6 testbed

This document provides a step by step explanation on the setup process for an FMIPv6 (Fast Handovers for Mobile IPv6, RFC4068) testbed. Please keep in mind that this document presents a testbed such as the one used for developing the fmipv6.org implementation and may not correspond to your needs: hardware and/or software requirements may vary depending on your particular setup.

The Testbed

                                 Uplink
                                    |
                                    | 2001:660:4701:ffff::2
                                    | eth0
                              +-----------+
                        eth2 \|   Home    |/ eth3
          2001:660:4701:1::1 /|   Agent   |\ 2001:660:4701:2::1
                              +-----+-----+
                                    | eth1
                                    | 2001:660:4701:3::1
                                    |
                                    |
                                    |
          2001:660:4701:3::2        |        2001:660:4701:3::3
   +------------+ eth0         +---------+         eth0 +------------+
   |    AR 1    |--------------|   Hub   |--------------|    AR 2    |
   |            |              +---------+              |            |
   +------------+                                       +------------+
         /\ eth1                                         eth1 /\
            2001:660:4701:4::1             2001:660:4701:5::1

The top router, which is also acting as a Home Agent, has four interfaces:

• the uplink, in this example eth0;
• one link connected to the backbone, in this example eth1;
• an interface, eth2, used by the Correspondent Node to connect;
• and an interface, set as the home network, in this example eth3.

Both Access Routers are connected to the backbone through their eth0 interfaces and offer wireless connectivity through eth1 which is either a wireless card or a wired interface directly connected to an 802.11 dedicated Access Point. The same is valid for eth2 and eth3 on the Home Agent.

Requirements

Hardware

The following hardware is needed to set up an operational testbed:

• 1 router acting as a Home Agent;
• at least 2 Access Routers;
• Access Points;
• Mobile Node and Correspondent Node;
• hub and cables :o)

NOTE: We first used Soekris net4521 cards for routers and despite slightly lower performance, which mostly showed when creating inter router tunnels, they served their purpose very well. Yet, for purely conventional reasons, we decided to switch to a set of Twisters, which apart from being more powerful are also a more convinient for an development platform where updates, changes in configuration as well as a more complete set of tools are needed.

Any Linux supported wireless card should work with fmipv6.org implementation. We nevertheless achieved best performances with cards based on an Atheros chipset with a few improvments of the Madwifi driver. We hope these changes will soon be integrated into Madwifi distribution to facilitate the use of FMIPv6.

Software

Requirements for the Home Agent:

• routing daemon (e.g. quagga);
• RA daemon (e.g. radvd);
• Linux kernel with MIPL2 patch applied;
• MIPL2 daemon.

Requirements for both Access Routers:

• routing daemon (e.g. quagga);
• RA daemon (e.g. radvd);
• Linux kernel with MIPL2 patch applied;
• fmipv6-ar daemon.

And finally, the Mobile Node needs:

• MIPL2 modified kernel (with a minor modification for better fmipv6.org performance) and userspace daemon (also slightly modified);
• fmipv6-mn daemon.

Setting up the Testbed

Setting up a fully functional IPv6 network

Before starting experimentation with FMIPv6, we need a fully functional IPv6 network. All nodes should be able to communicate with (send packets to) each other. This is a crucial part. If, for example, an AR is not able to reach the HA, then BUs coming from behind it will not create any bindings. A good way of verifying connectivity is through the "ping" program.

We'll give brief instructions on how we are to get IPv6 routing up in our testbed. For more detailed manual on setting up an IPv6 network, you can read Peter Bieringer's excellent Linux IPv6 HOWTO.

NOTE: you may choose to set up static routes, in this case you do not need to install and configure quagga or any other routing software.

In case you want dynamic routes (well... good choice) you'll need to run a routing daemon. Quagga comes with many routing daemons but for IPv6 routing you may choose between ospf6d and ripngd. We used the latter in our examples.

Don't forget to activate zebra and ripngd daemons on the routers:

Zebra daemon takes care of your interface, it configures them for you. Let's do that on the Home Agent:

NOTE: you may need to define a static default route if you don't receive ripng advertisements through your uplink in case you need internet connectivity.

And configure ripngd:

Let's do the same for the Access Routers:

And for ripngd:

If everything is OK, you should now be able to ping any host on your new network from any other machine in the testbed.

Broadcasting RAs

Stateless address autoconfiguration in IPv6 requires periodic broadcasts of Router Advertisement messages. We will be using radvd for doing just that.

The /etc/radvd.conf file on the Home Agent should contain:

The /etc/radvd.conf file on the Access Routers should look the following:

Configuring MIPL (for Mobile IPv6)

For complete instructions on building and configuring MIPL you should read the proper documentation provided with the project itself.

Here is the configuration file we use on the Home Agent:

Then configure your Mobile Node.

Now your Mobile Node should be able to move from one network to another. It may take time for the MN to retrieve its Care-of-Address on the new link, due to large intervals in RA broadcasts. Note that this does not affect FMIPv6 mobility but if you need faster address autoconfiguration without FMIPv6 and flooding your links doesn't bother you, you may lower these values to the ones recommended in RFC3775 (i.e. MinRtrAdvInterval=0.03s and MaxRtrAdvInterval=0.07s).

Configuring FMIPv6 daemons

Sorry, no doc for now! Read fmipv6.org manpages.

Testing

No doc neither. Please help us by submitting.