From 35C3 Wiki

There will be a network! Available in both wired and wireless flavours Be sure to read the Survival Guide before connecting your devices.

Rules of Conduct

  • Be fair! Do not do to others what you do not wish done to yourself! 🌈
  • Protect your computer! We cannot be held responsible for any damage your computer may face due to attachment to our network. Be reminded that both internet access and the local network are unfirewalled and unfiltered. Even well-maintained systems can be attacked and get hacked, even more so at a hacker event.
  • Be nice to wireless infrastructure! Consider these rules.
  • Do not run your own DHCP server! Doing so is harmful.
  • Do not send IPv6 Router Advertisements.
  • Do not ARP spoof or otherwise impede the operation of the network!
  • While we are generally quite able to find and disconnect you in case of network misuse if necessary, we still prefer to not have to do so and that everybody respects the other visitors.
  • Think twice before you do something that affects others! If you hack someone, you might be prosecuted. Be aware that we cannot prevent law enforcement from acting within or related to our network. 👮🚨🚔

Wired 〰️

  • On many tables and in the rooms you can connect via RJ-45 to the wired network.
  • Most ports provide Gigabit Ethernet.
  • Bring a 15m-20m cable for each device you want to connect.
  • Optionally, bring & connect a small ethernet switch when connecting multiple devices. Please disable Spanning-Tree Protocol if you would connect a managed switch.

Wireless 📶

You can't live without wireless access, so we've built an awesome wireless network again.

🤔 TL;DR, use our easy setup tools for Android Apple or Windows for secure wifi connectivity.


The following SSIDs are provided:

  • 35C3 (WPA2 802.1X (see below), 5GHz) ✅ c3noc recommended ✅
  • 35C3-legacy (WPA2 802.1X (see below), 2.4GHz)
  • 35C3-insecure (open, 2.4GHz+5GHz)
  • 35C3-things (WPA2-PSK = congress2018, 2.4GHz+5GHz)
    • For internet-connected "things" that require WPA2-PSK. Provides Congress-only inbound firewalling.

WPA2 802.1X, encryption

Due to popular demand (and with security in mind) we provide WPA2 802.1X. This will encrypt your traffic, preventing attackers from sniffing your data. Keep in mind that this won't protect you from other network attacks and you should still be aware that you are at a hacker conference! Your link layer should be secure if you do certificate checking (see below).

You might think: "WTF!? Do I need to register a user and password blah, blah". Fortunately not. You can use any username/password combination using EAP-TTLS with PAP to login (example: "user: fbhfbhiaf pass: bgufwbnkqo" is valid), because we don't care who logs in and who you are. We just want to encrypt your data.

Users which use MSCHAPv2 (like Windows users with default 802.1X supplicant) should use a fixed username and password. You can use "35C3/35C3" or "guest/guest" as "username/password".

Client Settings

Also see Static:Network/802.1X client settings for a list of OS-specific client settings.

SSID: 35C3 or 35C3-legacy


Phase 1: EAP-TTLS
Phase 2: PAP


Phase 1: PEAP
Phase 2: MSCHAPv2 or EAP-MSCHAPv2 or PAP

CN =
CA = DST Root CA X3
SHA256 Fingerprint = 11:9C:E1:A0:7B:8C:51:1E:8D:3D:A9:83:21:F2:9E:91:8B:D3:95:1D:14:93:72:41:7B:10:EE:9D:AC:BF:66:D8

Make sure you check the certificate in order to know you are connecting to the correct network (you should check on both the CN and the CA). Check here for the complete certificate.

Services / VLANs

Previously there were separate SSID's available for additional services. We're using WPA2 802.1X to push your client in the correct VLAN. The reason we are doing this is to keep the number of SSID's per wireless band to a minimum; this way we are saving airtime by not wasting it too much with 802.11 beacons/mgmt-frames. Use the following user/password combinations:

  • 35C3/35C3 or 35c3/35c3 or guest/guest (for regular user VLAN - for devices that have correctly implemented MSCHAPv2, like Windows)
  • outboundonly/outboundonly (Allows only outbound traffic; giving users basic protection and a way to save battery usage)
  • congressonly/congressonly (Same as above, but does only for inbound traffic from the Congress network)

Please note the username AND password are case-sensitive.

💩 2.4GHz & 5GHz

The 💩2.4GHz spectrum is very limited. Previously we've tried to use the vendor implemented workarounds like band-steering and band-select to persuade clients to use 5GHz. This might work in a controlled enterprise environment, but it doesn't work with 15000 hackers with 50 different operating systems.

The SSID 35C3 is 5GHz only. The SSID 35C3-legacy is 2.4GHz only. If your client supports both, don't use the 35C3-legacy SSID. If you only see the 35C3-legacy SSID, consider upgrading your device. We cannot guarantee that 💩2.4GHz works.


To keep the wireless working for you, keep a few things in mind:

  • We're aware you can break the WiFi infrastructure. We're hoping that you won't and don't want to be chased by 15000 hackers through Leipzig.
  • If you want to download terabytes of data, you might be better off connecting to the wired network
  • Don't set up your own accesspoint. However, if you have no other choice (for running experiments and such), please be nice and consider these rules:
    • Assembly areas only.
    • Please do not operate non-WiFi/analog equipment in these frequencies.
    • 2.4GHz: use channels 1, 5, 9 or 13 @ 20MHz. Disable 802.11b.
    • 5GHz: use channels 36 or 140 @ 20MHz.
    • Minimum data-rate = 12Mbit/s, also for beacon-rate. Beacon interval 100ms or higher.
    • Limit the number of broadcasted BSSID's per radio to 1 or 2. No SSID spamming etc is allowed.
    • Do not prefix your broadcasted ESSID(s) with "35C3". Do not use "35C3" as your ESSID. Do not use other well-known ESSIDs.
    • Do not use high-gain antennas.
    • Limit your transmit-power for example to 6dBm or 4mW.

Helpdesk 🆘

NOC Helpdesk location (c3nav)

If you have questions about the network or need help connecting or want to drop off a server for collocation during the event, drop by the friendly people of the NOC Helpdesk, located on level +1 of the CCL near the elevators.


This is a list of companies providing network hardware and connectivity services. The event would not have been possible without their support (and a few unlisted), and we thank them for it.

Who For
Supporter-babiel.jpg Servers
Supporter-corebackbone.png IP Uplink
Supporter-dtag.png IP Uplink
Supporter-adva.png Optical Transport Equipment
Supporter-bcix.png Peering Port
Supporter-enviatel.png Dark Fibre
Supporter-eventinfra.png Network equipment loan
Supporter-exaring.png Longhaul Spectrum/Wavelength
Supporter-flexoptix.jpeg Optical Networking Equipment
Supporter-gasline.jpg Longhaul Spectrum/Wavelength
Supporter-globalways.png Optical Transport Equipment
Supporter-hlkomm.png Dark Fibre
Supporter-ipb.png Colocation
Supporter-juniper.png Network Equipment
Supporter-GTT.png IP Uplink
Supporter-proact.png Network Equipment
Supporter-pylonone.png WiFi Network Equipment
Supporter-retn.png IP Uplink
Supporter-syseleven.png IP Uplink and Network Equiipment

Twitter 🐦

The CCC NOC team has a Twitter account: @c3noc

Archived page - Impressum/Datenschutz