[Planetlab-users] TCP raw Sockets in planet lab (AGAIN)

[Mark Huang]

Luis Carlos Erpen de Bona wrote:
> Its start easy, on 10.0.0.1 capture the data going out 
> to 10.0.0.2, send by a TCP tunnel for the correspondent real
> IP.  At the target I'm supposed to deliver the data to
> the application with source 10.0.0.1. But it's failing.
> Bug in my code or planetlab feature?

As Christoph mentioned, you cannot send packets with a non-local source 
IP address, including RFC1918 addresses such as 10.0.0.0/8. Even if you 
could, no router in its right mind would forward such packets.

Are you trying to build an overlay network? If so, the new TUN/TAP 
feature of VNET, which will rollout to production nodes very shortly, 
may help:

http://www.planet-lab.org/doc/vnet.php

In short, very soon, every PlanetLab node will have a virtual TUN/TAP 
device "tap0" that will be configured with a unique (to each node) 
RFC1918 10.0.0.0/8 address. An overlay network that we are currently 
building called the PlanetLab Backbone (PLB) links all of these devices 
together into a single fully connected mesh. The TUN/TAP interface is 
generic, however; any slice may send and receive its own packets via 
/dev/net/tun, and implement their own overlay networks within their own 
slices. More details about PLB are forthcoming.

--Mark
PlanetLab Operations