You can find more complete explanations on my blog.
This lab makes use of a special kernel. The configuration of this
kernel is provided in config-3.6+ecmp. The kernel used it is
7fe0b14b725d6d09a1d9e1409bd465cb88b587f9 from net-next. You can use
anything from Linux 3.5.
The kernel configuration is pretty minimal and is targeted for this lab. It should have the necessary drivers to use virtio (but nothing else). There is no module. It also includes 9P support to be able to mount a directory from guest.
You need the following patches:
To get a patch for overlayfs, you need a kernel tree from git with
both Linus tree and Miklos tree. Suppose you have cloned net-next and
you have applied the appropriate IPv6 ECMP patch in a dedicated branch
named feature/ecmp-ipv6.
$ git remote add torvalds git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
$ git fetch torvalds
$ git remote add overlayfs git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs.git
$ git fetch overlayfs
$ git merge-base overlayfs.v15 v3.6
4cbe5a555fa58a79b6ecbb6c531b8bab0650778d
$ git checkout -b feature/ecmp-ipv6+overlayfs
$ git cherry-pick 4cbe5a555fa58a79b6ecbb6c531b8bab0650778d..overlayfs.v15
We require a complete filesystem hosted into some directory. This is
not really important what distribution is used. It is possible to use
the root filesystem of the currently running system. A debootstrap is
OK. You can use something fancier like pbuilder or schroot.
Quagga is expected to be compiled with the following options:
../configure --enable-vtysh --localstatedir=/opt/quagga/run \
--prefix=/opt/quagga --sysconfdir=/opt/quagga/etc \
--enable-multipath=64 \
CFLAGS="-O0 -g"
To run the lab, run:
$ ./setup
If you want to run the lab inside an alternative root file system, use:
$ export ROOT=/var/cache/pbuilder/bases/debian.sid.lab.amd64
$ sudo bind --mount -o ro /home ${ROOT}/home
$ ./setup