Router Advertisement Tools
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This is ratools, a fast, dynamic, multi-threading framework for creating, modifying and sending IPv6 Router Advertisements (RA).

Quick Introduction

See this 4 minute video to get a brief overview.


The basic idea is to have two programs. On the one hand a powerful CLI, called ratools/ractl, for manipulating the configuration. And on the other hand an efficient, non-bloated stable daemon process, called ratools/rad. As depicted below, both programs communicate with each other via an UNIX socket.

                          |                  +-- eth0
                          |  ratools/rad     +-- eth1
                          |                  +--  :
                          |           Daemon +-- ethN
+------------------+          |
|                  |          |
|  ratools/ractl   |          |
|                  +----------+ AF_UNIX
|              CLI |

The internal structure of ratools/rad looks like this:

   + KERNEL                        + INTERFACES
   |                               |
+--+-------------+              +--+-------------+
| Netlink Socket |          +-->|   RAW Socket   +---+
+--+-------------+          |   +----------------+   |
   |                        |                        |
   v                        |                        v
+----------------+       +--+-------------+       +----------------+
| Configuration  +---+   |  Packet Delay  |<------+  RS Listener   |
|   Database     |   |   |    Threads     |       |     Thread     |
+----------------+   |   +----------------+       +--+-------------+
   ^                 |      ^                        |
   |                 |      |                        |
+--+-------------+   |   +--+-------------+          |
|  UNIX Socket   |   +-->|   RA Worker    |<---------+
+--+-------------+       |    Threads     |
   |                     +----------------+
   + CLI


Although ratools is complex from the inside, the code looks very POSIX-ish from the outside. Thus, bulding is relatively easy. Clone the repository and type make. It is as simple as that!

$ git clone
Cloning into 'ratools'...
$ cd ratools/src/
$ make

Quick start

First start the daemon (ratools/rad)

# rad --loglevel info
ratools/rad v0.6.1 (March 2015)
Written by Dan Luedtke <>
Log: Level set to `info'.
Info: Netlink: Thread started.
Info: Listener: Thread started.

Now use the CLI (ratools/ractl) to create a new RA

# ractl ra@dummy0 create

How about advertising the link MTU?

# mtu@dummy0 create
# mtu@dummy0 enable

It is also nice to let clients know the source link-layer address.

# sll@dummy0 create
# sll@dummy0 enable

Of course we like to advertise at least one prefix!

# pi0@dummy0 create
# pi0@dummy0 set prefix 2001:db8::/64
# pi0@dummy0 enable

Nice routers come with recursive DNS server addresses as well:

# rdnss0@dummy0 create
# rdnss0@dummy0 add server 2001:db8::53
# rdnss0@dummy0 enable

Let's enable our little fella:

# ra@dummy0 enable

Have at look at your ICMPv6 masterpiece using the CLI

# ractl show
Router Advertisement `ra@dummy0':
  State:                  Fading in       (34%)
  Created:                2014-05-30 16:32:58
  Updated:                2014-05-30 16:33:46
  Version:                17/18           (Compilation scheduled)
  Interface ID:           4               (dummy0)
  Interface State:        1               (Up)
  Interface MTU:          1500
  Hardware Address:       1a:39:b3:80:f4:cc
  Link-local Address:     fe80::1839:b3ff:fe80:f4cc
  Maximum Interval:       600             (0d 0h 10m 0s)
  Minimum Interval:       198             (0d 0h 3m 18s)
  Solicited/Unsolicited:  1/0
  Unicast/Multicast:      0/1
  Total RAs:              1               (88 Bytes)
  Next RA scheduled:      2014-05-30 16:34:02
  Current Hop Limit:      64
  Managed Flag:           0               (No Managed Address Configuration)
  Other Managed Flag:     0               (No Other Managed Configuration)
  Home Agent Flag:        0               (No Mobile IPv6 Home Agent)
  Router Preference:      00              (Medium)
  NDP Proxy Flag:         0               (No NDP Proxy)
  Lifetime:               1800            (0h 30m 0s)
  Reachable Time:         0               (0h 0m 0s 0ms)
  Retransmission Timer:   0               (0h 0m 0s 0ms)
  Link-MTU Option `mtu@dummy0':
    State:                Enabled
    Auto-detection:       On
    Link-MTU:             1500
  Source Link-layer Address Option `sll@dummy0':
    State:                Enabled
    Auto-detection:       On
    Hardware Address:     1a:39:b3:80:f4:cc
  Prefix Information Option `pi0@dummy0':
    State:                Enabled
    On-link Flag:         1               (On-link Prefix)
    Autonomous Flag:      1               (Autonomous Address Configuration)
    Router Address Flag:  0               (No Mobile IPv6 Router Address)
    Valid Time:           2592000         (30d 0h 0m 0s)
    Preferred Time:       604800          (7d 0h 0m 0s)
    Prefix:               2001:db8::/64
      Warning: Documentation prefix!
  Recursive DNS Server Option `rdnss0@dummy0':
    State:                Enabled
    Lifeime:              900             (0d 0h 15m 0s)
    Server:               2001:db8::53

To save your work you can dump the configuration:

# ractl dump
ra@dummy0 create
mtu@dummy0 create
mtu@dummy0 enable
sll@dummy0 create
sll@dummy0 enable
pi0@dummy0 create
pi0@dummy0 set prefix 2001:db8::/64
pi0@dummy0 enable
rdnss0@dummy0 create
rdnss0@dummy0 add server 2001:db8::53
rdnss0@dummy0 enable
ra@dummy0 enable

Best pratice is to save the configuration to a file:

# ractl dump > example.conf

If you want to restore the configuration at a later time, just pipe it into ratools/ractl:

# ractl < example.conf

Please make sure to always use the latest version before reporting bugs. Thanks!

# ractl version



Copyright 2013-2015 Dan Luedtke <>

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
See the License for the specific language governing permissions and
limitations under the License.