29 Mar
2014
29 Mar
'14
12:08 p.m.
On Fri, Mar 28, 2014 at 3:03 PM, Eric Fort <eric.fort(a)gmail.com> wrote:
(Please trim inclusions from previous messages)
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It would seem to me that while due to the fact we are tunneling most
everything we may have a logical full mesh but far from a physical full
mesh. What does a tunneled logical full mesh really accomplish for us
other than making things all the more complicated?
Right now it allows small/medium sized islands of amateur packet radio
networks to interconnect with others around the planet at speeds faster and
more reliable than HF or VHF.
Wouldn't traditional
peering and routing done "the normal way" be much easier?
Not really because most networks are point to point (ie: you connect to
your work VPN - not you connect to your work VPN which interconnects with
every other VPN in the world). This essentially is a hack to backbone a
semi-private network on top of the public internet.
I can see a
valid place for nailing up vpn links and various tunnels, i.e. last mile
access and tying islands together though something other than IPIP with
links negotiated on a peering basis as needed, but what does a full logical
mesh of tunnels give us? It seems that since it's built of tunnels and
thus virtual rather than physical we just unnecessarily complicate the mess
wherein the tunneled traffic and the tunnels themselves end up taking
multiple and somewhat changing hops to get from one end to another.
Yup, nothing's perfect.
IP was
designed such that I could hand a packet off and basically go, "ok, now
it's your problem to deliver it (on a best effort basis)", thus I shouldn't
need to know every conceivable route to every conceivable endpoint. What
prevents us from using it that way?
Because the internet isn't built that way. You still need a source and
destination address. You still need routers able to figure out how to get
your packet from point A to point Z via points B,C,Q and V. And your
packets need to know how to return back to you through said points. The way
the current network works is that it sends a routing table to all
participants of all these little islands of "44net" and how they could be
reached over the public internet. And mind you, for it to work correctly,
the traffic has to be effectively routable back to you without being
dropped into a blackhole or routing loops occurring. One can just
substitute 44/8 for 10/8 and the same problems are there.
The simplest way of routing a non-routable network is through encapsulation
for which IPIP was chosen as it's part of the TCP/IP network protocol.
This allows everyone to be part of the network while not having control or
bandwidth being focused at any one single location.
A significantly harder solution would be to use BGP which is what is used
on the larger internet. But there are many, many reasons why you don't
want just anyone manipulating BGP routes. One wrong command and you could
send China's internet traffic to Togo. Or create routing loops which would
cause large interruptions not only for yourself but for a multitude of
other people on the internet.
Most residential ISP's will not let you insert 44/8 addresses onto their
networks. Even commercial hosting and colocation providers really want to
see justification and the proper I's and T's dotted and crossed before they
will host a 44/8 subnet for you as it's still not a trivial change. Then
there is the problem of encapsulated and non-encapsulated. The few 44/8
subnets that have broken off the UCSD router are able to route across the
internet just like anyone else but cannot reach other 44net islands that
run the encapsulated tunnels without going back to the encap munge because
those other islands either don't know how or are unable to reach them due
to upstream providers blackholing 44/8 traffic as nonroutable.
One might suggest that we can just create a 44net VPN that we all connect
into via PPTP or other means but who pays the hosting bill for that?
Bandwidth and hosting still costs money at the end of the day as Netflix
found out. And we don't have the advantage of doing commercial "peering"
as our networks cannot be used for commercial purposes.
That's all I got...