Preliminary Mininet Installation/Configuration Notes
Development version, March 2010
---
Disclaimer: this is not (yet) a 'release'; things may be broken.
These installation notes assume you understand how to do things
like compile kernels, apply patches, configure networks, write code,
etc.. If this is unfamiliar territory, we recommend using one of
our pre-built virtual machine images from:
http://www.openflowswitch.org/foswiki/bin/view/OpenFlow/MininetGettingStarted
If you are Linux-savvy and wish to take on the challenge of installing
Mininet and its dependencies from scratch, here are the requirements:
1. Core Mininet installation
To install Mininet itself, with root privileges:
# make install
This places the mininet package in /usr/lib/python-2.5/site-packages/,
so that 'import mininet' will work, and installs the primary mn
script (mn) as well as its helper utility (mnexec.)
2. Linux Kernel requirements
Mininet requires a kernel built with network namespace support enabled,
i.e. with CONFIG_NET_NS=Y
If your kernel doesn't support it, you will need to build and install a
kernel that does! >= 2.6.33 works best, but requires a patch to
ofdatapath and to tun.c (see patches [1] and [2], below.)
2.6.26 works with CONFIG_NET_NS enabled and no additional patches, but
it is much slower at removing veth interfaces, resulting in much slower
switch shutdown.
For scalable configurations, you might need to increase some of your
kernel limits. Sample params are in sysctl_addon, which can be appended to
/etc/sysctl.conf (and modified as necessary for your desired
configuration):
sudo su -c "cat sysctl_addon >> /etc/sysctl.conf"
To save the config change, run:
sudo sysctl -p
3. OpenFlow software and configuration requirements
Mininet requires either the reference OpenFlow switch implementation
(from openflowswitch.org) or Open vSwitch (openvswitch.org) to be
installed. "make test" requires the reference user and kernel
space implementations as well as Open vSwitch. Note the kernel
implementation is not currently included in OpenFlow 1.0.
To switch to the most recent OpenFlow 0.8.9 release branch (the most
recent one with full NOX support):
git checkout -b release/0.8.9 remotes/origin/release/0.8.9
To compile for Linux >= 2.6.33, you may need to apply patch [1]
included below.
Mininet will automatically load and remove kernel module dependencies for
supported switch types, using modprobe and rmmod - but these modules must be
in a location where modprobe can find them.
See ~/mininet/util/modprobe_setup.sh for an example.
The reference OpenFlow controller (controller(8)) only supports 16
switches by default! If you wish to run a network with more than 16
switches, please recompile controller(8) with larger limits, or use a
different controller such as nox. A patch to controller(8) is included
as patch [3] below.
4. Other software dependencies
To run the iperf test, you need to install iperf:
sudo aptitude/yum install iperf
We assume you already have ping installed. ;-)
To use xterm or sshd with Mininet, you need the following:
sudo aptitude/yum install sshd xterm screen
Some examples may have additional requirements - consult the specific
example file for details.
5. Other notes and recommendations
Mininet should probably be run either on a machine with
no other important processes, or on a virtual machine.
Multiple concurrent Mininet instances are not supported!
Good luck!
--- Patches and Footnones ---
[1] OpenFlow Reference Implementation patch for Linux 2.6.33/2.6.33.1
The OpenFlow kernel reference implementation does not compile out of the box
on Linux 2.6.33/2.6.33.1 with network namespaces enabled.
The following workaround modifies it to always use the root namespace, and should
enable it to work with Mininet under 2.6.33.x:
diff --git a/datapath/datapath.c b/datapath/datapath.c
index 4a4d3a2..365aa25 100644
--- a/datapath/datapath.c
+++ b/datapath/datapath.c
@@ -47,6 +47,9 @@
#include "compat.h"
+#ifdef CONFIG_NET_NS
+#include <net/net_namespace.h>
+#endif
/* Strings to describe the manufacturer, hardware, and software. This data
* is queriable through the switch description stats message. */
@@ -259,7 +262,11 @@ send_openflow_skb(const struct datapath *dp,
struct sk_buff *skb, const struct sender *sender)
{
return (sender
- ? genlmsg_unicast(skb, sender->pid)
+#ifdef CONFIG_NET_NS
+ ? genlmsg_unicast(&init_net, skb, sender->pid)
+#else
+ ? genlmsg_unicast(skb, sender->pid)
+#endif
: genlmsg_multicast(skb, 0, dp_mc_group(dp), GFP_ATOMIC));
}
[2] Linux kernel 2.6.33/2.6.33.1 tun driver patch
The tun driver in Linux 2.6.33/2.6.33.1 doesn't work correctly in a network
namespace. As a result, running the user datapath in a network namespace
(e.g. as is done in examples/scratchnetuser.py) will cause a kernel panic
when sysfs cannot create an entry for a tap interface, since the tun network
device has a missing parent kobj. As a workaround, the following patch
skips creating the sysfs entries when this is the case. This is an acceptable
workaround as long as sysfs entries for tap interfaces are not being actively
used (and they are not currently in Mininet.)
diff linux-2.6.33.1/drivers/net/tun-orig.c linux-2.6.33.1/drivers/net/tun.c
1009c1009,1011
< if (device_create_file(&tun->dev->dev, &dev_attr_tun_flags) ||
---
> /* BL workaround: check for null parent kobj */
> if (!tun->dev->dev.kobj.sd ||
> device_create_file(&tun->dev->dev, &dev_attr_tun_flags) ||
[3] Patch to reference OpenFlow controller to allow more than 16 switches
diff --git a/controller/controller.c b/controller/controller.c
index 41f2547..6eec590 100644
--- a/controller/controller.c
+++ b/controller/controller.c
@@ -58,8 +58,8 @@
#include "vlog.h"
#define THIS_MODULE VLM_controller
-#define MAX_SWITCHES 16
-#define MAX_LISTENERS 16
+#define MAX_SWITCHES 4096
+#define MAX_LISTENERS 4096
struct switch_ {
struct lswitch *lswitch;