[Dump] A Babel experiment at funkfeuer.at

[Juliusz Chroboczek]

> I use something like "babel -g 2222 eth1 sit1" to start babel

We use

  babel -D -g 33123 -k 20

I suggest you use port 33123 for the local interface, just like we do, so
that our tools (see below) can interoperate.

> monitor it via "telnet ::1 2222" - do you recommend something else
> then telnet?

Yes.  Log into your OpenWRT box using

  ssh -L 33123:ip6-localhost:33123 ...

Then, you can telnet ::1 33123 on the machine from which you logged in,
which means you can use the nice local telnet rather than the limited
version included in OpenWRT.

The interface is actually not designed for human beings, it's designed for
a GUI.  Two students of mine have been working on the GUI for the last six
months, their current version is available by doing

  darcs get http://www.pps.jussieu.fr/~jch/software/repos/BabelTool

Yes, the code is a mess, but the algorithms are pretty sweet.  (We'll try
to clean the codebase up over the next months.)  The port is hard-wired to
33123.

> It would be nice if babel would accept connections on some routable
> addresses or on 127.0.0.1.

Noted.

> When babel is running on a small router, then it prints messages
> "netlink_read: recvmsg(): No buffer space available" every now and
> then.

Yep, I don't know why.  Babel will recover cleanly, but I'd like to
understand what's going on.

> Ok, I used this as a start. Next I'll play with non default
> metrics. Especially tunnels should be expensive instead of having the
> same link cost as a cable ... 

Yep.  I'm thinking of measuring RTT times and doing that automatically, but
it's pretty low on my TODO list.

> So far I have only played with sit tunnels, which works fine.

That's a bad idea, since SIT cannot carry IPv4, so it means that all the
infrastructure will need changing if you ever decide to switch to hybrid
routing.  I strongly recommend GRE, which is portable and able to carry
multiple protocols.

> I suggest that we start with two tunnels between your site and Vienna.

No can do -- we're using OpenVPN (negotiated with our sysadmin), and
I really don't feel like going through the negotiations again.  I'll get in
touch with you through private mail.

                                        Juliusz