<s>
dn42	B-Application
is	O
a	O
decentralized	O
peer-to-peer	O
network	O
built	O
using	O
VPNs	B-Application
and	O
software/hardware	O
BGP	B-Protocol
routers	B-Protocol
.	O
</s>
<s>
While	O
other	O
darknets	B-Operating_System
try	O
to	O
establish	O
anonymity	O
for	O
their	O
participants	O
,	O
that	O
is	O
not	O
what	O
dn42	B-Application
aims	O
for	O
.	O
</s>
<s>
It	O
is	O
a	O
network	O
to	O
explore	O
routing	B-Protocol
technologies	O
used	O
in	O
the	O
Internet	O
and	O
tries	O
to	O
establish	O
direct	O
non-NAT-ed	O
connections	O
between	O
the	O
members	O
.	O
</s>
<s>
The	O
network	O
is	O
not	O
fully	B-Architecture
meshed	I-Architecture
.	O
</s>
<s>
dn42	B-Application
uses	O
mostly	O
tunnels	O
instead	O
of	O
physical	O
links	O
between	O
the	O
individual	O
networks	O
.	O
</s>
<s>
Over	O
the	O
VPN	B-Application
or	O
the	O
physical	O
links	O
,	O
BGP	B-Protocol
is	O
used	O
for	O
inter	O
AS	B-Architecture
routing	B-Protocol
.	O
</s>
<s>
While	O
OSPF	O
is	O
the	O
most	O
commonly	O
used	O
protocol	O
for	O
intra	O
AS	B-Architecture
routing	B-Protocol
,	O
each	O
participant	O
is	O
free	O
to	O
choose	O
any	O
other	O
IGP	O
,	O
like	O
Babel	O
,	O
inside	O
their	O
AS	B-Architecture
.	O
</s>
<s>
The	O
DN42	B-Application
project	O
grew	O
out	O
of	O
the	O
popular	O
PeerIX	O
project	O
started	O
by	O
HardForum	O
members	O
in	O
mid-2009	O
.	O
</s>
<s>
The	O
founding	O
members	O
of	O
the	O
DN42	B-Application
project	O
tried	O
to	O
unsuccessfully	O
rekindle	O
the	O
PeerIX	O
project(through the private google group )	O
and	O
instead	O
formed	O
their	O
own	O
IPv6	O
only	O
network	O
,	O
successfully	O
scaling	O
it	O
to	O
the	O
size	O
it	O
is	O
today	O
.	O
</s>
<s>
Network	O
address	B-General_Concept
space	I-General_Concept
for	O
IPv4	O
consists	O
of	O
private	B-Protocol
subnets	B-Protocol
:	O
172.20.0.0/14	O
is	O
the	O
main	O
subnet	B-Protocol
.	O
</s>
<s>
Note	O
that	O
other	O
private	B-Protocol
address	I-Protocol
ranges	O
may	O
also	O
be	O
announced	O
in	O
dn42	B-Application
,	O
as	B-Architecture
the	O
network	O
is	O
interconnected	O
with	O
other	O
similar	O
projects	O
.	O
</s>
<s>
Most	O
notably	O
,	O
ChaosVPN	O
uses	O
172.31.0.0/16	O
and	O
parts	O
of	O
10.0.0.0/8	B-Protocol
,	O
Freifunk	O
ICVPN	O
uses	O
10.0.0.0/8	B-Protocol
and	O
NeoNetwork	O
uses	O
10.127.0.0/16	O
.	O
</s>
<s>
For	O
IPv6	O
,	O
Unique	B-Protocol
Local	I-Protocol
Address	I-Protocol
(	O
ULA	O
,	O
the	O
IPv6	O
equivalent	O
of	O
private	B-Protocol
address	I-Protocol
range	O
)	O
(	O
fd00::/8	O
)	O
are	O
used	O
.	O
</s>
<s>
Please	O
note	O
that	O
other	O
network	O
use	O
IPv6	O
addresses	O
in	O
this	O
range	O
as	B-Architecture
well	O
,	O
including	O
NeoNetwork	O
's	O
use	O
of	O
fd10:127::/32	O
.	O
</s>
<s>
In	O
order	O
to	O
use	O
BGP	B-Protocol
,	O
even	O
in	O
a	O
private	B-Protocol
environment	O
,	O
Autonomous	B-Architecture
System	I-Architecture
Numbers	I-Architecture
are	O
needed	O
.	O
</s>
<s>
dn42	B-Application
uses	O
several	O
private	B-Protocol
or	O
reserved	O
AS	B-Architecture
numbers	I-Architecture
ranges	O
,	O
including	O
64512	O
to	O
64855	O
and	O
76100	O
to	O
76199	O
.	O
</s>
<s>
Since	O
June	O
2014	O
,	O
dn42	B-Application
is	O
now	O
using	O
a	O
new	O
private	B-Protocol
range	O
,	O
4242420000	O
to	O
4242429999	O
,	O
part	O
of	O
larger	O
private	B-Protocol
range	O
defined	O
by	O
RFC	O
6996	O
.	O
</s>
<s>
While	O
some	O
participants	O
use	O
hardware	B-Protocol
routers	I-Protocol
,	O
most	O
participants	O
use	O
general	O
purpose	O
servers	O
or	O
virtual	O
machines	O
to	O
lower	O
their	O
cost	O
.	O
</s>
<s>
The	O
most	O
commonly	O
used	O
BGP	B-Protocol
implementation	O
used	O
in	O
dn42	B-Application
are	O
BIRD	B-Protocol
and	O
FRR	B-Protocol
,	O
but	O
some	O
participants	O
use	O
OpenBGPD	B-Application
,	O
XORP	B-Protocol
,	O
GoBGP	O
or	O
the	O
implementation	O
of	O
JunOS	B-Application
or	O
Cisco	B-Protocol
IOS	I-Protocol
.	O
</s>
<s>
Websites	O
and	O
services	O
hosted	O
on	O
the	O
Dn42	B-Application
network	O
often	O
use	O
the	O
dn42	B-Application
top-level	O
domain	O
.	O
</s>
<s>
The	O
dn42	B-Application
tld	O
is	O
not	O
an	O
official	O
IANA	O
top-level	O
domain	O
,	O
but	O
it	O
is	O
handled	O
through	O
the	O
dn42	B-Application
registry	O
.	O
</s>
<s>
Internal	O
anycast	O
servers	O
for	O
dn42	B-Application
are	O
found	O
at	O
172.20.0.53	O
,	O
172.23.0.53	O
,	O
and	O
fd42:d42:d42:54::1	O
,	O
fd42:d42:d42:53::1	O
.	O
</s>
