#FFMEET #Jitsi Freifunk

1. FFMUC goes wild
Tech talk at #rc3 28.12.2020

2. awlnx
● Annika Wickert
● Senior Network Engineer
● Twitter @awlnx
krombel
● Matthias Kesler
● IT Consultant
● Twitter @kr0mbel
Who are we?
pkoerner
● Peter Körner
● IT since CBM, 2C3, FF 6y,
DL9HCZ, working @Red Hat
● Twitter @pkoerner81929

3. FFMUC?
• Freie Netze München e.V. seit 2014
• Community Freifunk München seit 2004
• No registration of nodes
• Wifi
• #FFMEET
• DoH/DoT/DNSCrypt

4. Jitsi to close the social gap during corona
• An upcoming Freifunk Meeting was about to get canceled because of Corona
• Many people especially schools seemed in need of an easy to use conference
system
• “Freifunk verbindet”
• Christmas 2020

5. FFMEET appeared in the press

6. Technical challenges
• Scaling (nginx, prosody etc)
• Firefox a WebRTC nightmare
• Running on nightly builds
• Automation

7. Many participants and supporters!

8. Restart of Freie Netze München e.V.
• FNMUC was kinda abandoned
• We need an entity which can sign contracts and
acquire money
• Elections in July
• Since then many new members, many actions,
lots of ideas and high motivation

9. AS212567
• IPv4: 5.1.66.0/24 + 185.150.99.0/24
• IPv6: 2001:678:e68::/48 + 2001:678:ed0::/48
• When we need to switch datacenters we keep the address space
• We can multi-home much easier
• More possible sponsors
• We can join Internet Exchanges! #PeeringFamily
• Abuse handling is done by FNMUC e.V.

10. Preparing the new datacenter
● Pre-Installing everything possible
● Switching to Ubuntu 20.04 from Debian (mostly) stretch
● Run an overlay network for easier cross-site communication (Nebula)
● Much SaltStack code: https://github.com/freifunkMUC/ffmuc-salt-public

11. Journey to vienna

12. Vienna!

13. We are online!

14. Use more bandwidth!
• New DC has a bigger uplink
• Users cannot use it, because fastd does not perform very well
• L2TP performs very good but has no encryption
• We experimented with Wireguard before and were very happy with it

15. Wireguard vs fastD
• FastD is a single threaded userspace process
• Wireguard runs in kernel space thus has to be multithreaded
• Wireguard cannot transport Layer2 Protocols - B.A.T.M.A.N. is one ...
• We need another encapsulation which solves this problem => VXLAN
WireguardVXLANB.A.T.M.A.N.

16. Gateways
• Everything is automated with Saltstack
• systemd-networkd takes care of all interfaces
• 800 - 1000 Nodes per Gateway are easy
• We run whole FFMUC on just two gateways

17. We are pioneering much stuff
• There was no systemd-networkd integration for B.A.T.M.A.N.
=> So we wrote it: https://github.com/systemd/systemd/pull/17252
• There was no firmware integration
=> So we wrote it:
https://github.com/freifunk-gluon/community-packages/pull/6
• There was no daemon to accept wireguard keys
=> So we wrote it: https://github.com/freifunkMUC/wgkex

18. How does it work?
• Wireguard Peers on the gateways are created by wgkex
• Allowed IP is derived from the publickey of the node
• VXLAN Forwarding database entry are created by wgkex

19. WGKex?

20. Debugging … Flamegraphs and Bugs
• Wireguard performs well but we have too much load on our gateways. Why?

21. Community
• Freifunk Darmstadt and Freifunk Regensburg helped a lot during development
of wgkex!
• B.A.T.M.A.N. developers helped a lot during debugging the performance issue
and created many bugfixes
• Everything is opensource and available on Github
https://github.com/freifunkMUC
• More background and all fixes:
https://ffmuc.net/freifunkmuc/2020/12/03/wireguard-firmware/

22. So is it faster?

23. Other Services
• Chat for our Community (and people interested in Jitsi ;) ) https://chat.ffmuc.net
• Public DoH/DoT/DNSCrypt resolver https://doh.ffmuc.net

24. Encrypted DNS
• As we appeared in c’t much growth the last month (link in appendix)

25. New datacenter in munich

26. Much code ...

27. Feedback, comments
Wir freuen uns über jede konstruktive Kritik:

28. Community & Social Media

29. We need members and supporters
• We have monthly costs for data centers, IP space etc.
• We have a association called Freie Netze München e.V.
• We only have a few number of admins at the moment
• New ideas christmas presents
https://ffmuc.net/freifunkmuc/2020/12/12/weihnachtsaktion/
=> We need more people! Sign up here:
https://ffmuc.net/wiki/doku.php?id=ev:start
“Das andere
Weihnachts
geschenk!”

30. FFMUC at #rC3
• Jitsi/FFMUC Meet Raum 24/7: https://meet.ffmuc.net/ffmuc-rc3
• FFMUC Chat (Mattermost): https://chat.ffmuc.net/
• Wireguard background:
https://ffmuc.net/freifunkmuc/2020/12/03/wireguard-firmware/
• FFMUC Wiki Knowledge Base:
https://ffmuc.net/wiki/doku.php

31. More links
• Freifunk München Map: https://map.ffmuc.net
• Freifunk München: https://ffmuc.net
• Freifunk: https://freifunk.net
• Freifunk Karte: https://freifunk-karte.de
• RIPE Anchor: https://atlas.ripe.net/probes/6886/
• RIPE Stats: https://stat.ripe.net/as212567