FAQ

Frequently asked questions

Design of Penumbra

Why is there no "search"?

Search weakens your privacy too much. Instead of an active search where the user has to initiate broadcast of keywords, there is a constant lowlevel broadcasting of "advertisment" packets for content, which are captured by each node and held in a large FIFO queue in persistant storage. In this way available content is browseable without the user having to personally initiate broadcasting his interest.

But what about when he downloads the content itself!

His expression of interest is a private matter between him and his browser. The effect of it is to increase the score for acquiring chunks of that content, which can equally occur due to seeing external requests for that content and automatically forwarding for it.

Browser compatability

What browsers can I use to communicate with penumbrad?

Any SSLv2 or SSLv3 -capable browser (which is pretty much all modern browsers) should work fine. It is tested with Konqueror and Firefox here. Javascript is used now for the navigation and category select functionality.

Kernelside stuff

No Penumbra packets are received into penumbrad?

You may need to assign an IP address to the wireless interface before you can get packets through by listening on it. Either associate the wireless device normally to your network and use your normal IP, or force a bogus one on to the interface so the OS will allow packets through, eg



Note that the interface has to be "up", but that this isn't enough without an IP address. promisc is required for some wireless devices as well.

Penumbrad

I don't get any received packets into penumbrad, but if I tcpdump the interface, I can see the UDP packets? What's wrong?

Netfilter is doing its job as a firewall and disallowing the packets to reach penumbrad. Open UDP port 61442 using something like this



On Fedora/RHEL/CentOS, you can make that permanent across boots with this



or you can stick it in /etc/rc.local or whatever your distro provides.

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