Articles
Carsten Strotmann

The RIPE-javik logs: Day 1

The first day of RIPE 78.

May 21st, 2019

carsten@menandmice:~$ cat ~/ripe/ripejavik-day1.txt | blog-publish

The first day of RIPE 78 started with the welcome talk by RIPE chair Hans Petter Holen and the hosts of the meeting: Icelandic sea-cable provider Farice and RHnet, the university network provider of Iceland.

It was impressive to hear that Iceland has already achieved 80% Fiber-to-the-Home installation and will have 100% by 2025. In terms of Internet speed, Iceland is only second after Norway (for mobile Internet) and Singapore (for fixed line Internet).

After short talks by Andrew Sullivan, the president and CEO of ISOC, the Internet Society (the organisation that facilitates Internet Standards Processes such as those developed by the IETF, amongst other things) and Benno Overeinder for the RIPE Program Committee, probably the best known Icelander in the Internet community took to the stage: Ólafur Guðmundsson, inventor of DNSSEC and currently CTO of Internet accelerator Cloudflare.

IPv4 volatility

Ólafur’s topic was the volatility of IP addresses. While at the beginning of the Internet IP addresses were stable over a long time and could be used to identify a machine, this is not the case today. Mobile devices switch networks constantly, always getting new addresses. A smartphone can have more than 10 different IP addresses over the course of a single day, roaming across different mobile providers and wireless networks.

As Ólafur described, IP addresses cannot reliably be used to identify machines anymore. Still, many service providers, companies, and government agencies do that all the time, for

  • blacklisting,
  • geo-location,
  • to calculate online advertising prices by placing a value to the user using the IP address,
  • or to find the nearest content server.

IPv4 address brokerage makes the situation worse. Because there are no free IPv4 addresses left and many companies have not yet switched over to IPv6, IPv4 addresses are valuable (>20 US$ per address) and are for sale. When sold, these addresses change location, but providers of location databases cannot keep up with the changes and the databases become outdated and full of wrong data.

Roaming and routing

In the next talk, Alo Safari Khatouni spoke about the implication of mobile phone roaming in Europe. In his research, he has specifically looked into how IP data is being routed in roaming situations, and when the difference in latency and bandwidth impacts a roaming user’s experience.

He found no content discrimination (i.e. that certain data is being throttled during a roaming situation), but latency was certainly higher. Mobile network operators route the roaming traffic back to the home network, where it is then routed to the Internet. This means that for a customer of an US-based mobile network operator (MNO) who is in Iceland and trying to access a website in Iceland (to look up the weather conditions - vital information in Iceland!), the network data will be routed through the US MNO’s network. It’s no surprise that this is slower than staying in Iceland and accessing the data directly.

In the Q/A session following this talk, IPv6 evangelist Jan Zorz mentioned that he also experiences IPv6 Path-MTU-Discovery issues while being inside one of the MNO networks in Iceland. It may be that possibly someone is blocking ICMPv6 on the network.

ATLAS

In the first lightning talk, Christopher Amin from the RIPE NCC explained some of the security safety belts RIPE has built into the RIPE ATLAS system.

RIPE ATLAS is a network measuring networks, where ATLAS probes are distributed all around the world. These probes can be remotely controlled by researchers to make traffic measurements on the Internet from different points of the worldwide network. However, some probes are operated by private persons in their home networks and might be located in countries where access to certain Internet content is prohibited by law. Law enforcement might not be able to tell apart access from a real Internet device from that of an ATLAS probe.

To resolve this, RIPE has built in a host of security and safety measures to limit or block the access to sensitive Internet content, but also wants to add support for DNS-over-HTTPS (DoH) measurements to the ATLAS system. The problem here is that DNS-over-HTTPS looks, by design, like HTTPS traffic generated by a web browser. From the outside, one cannot see if the content requested is a website or DNS data. Enabling DoH measurements without restrictions can introduce risks for RIPE ATLAS probe operators. Christopher asked the RIPE community about their comments and how this challenge can be solved.

The second issue Christopher brought up was the use of EDNS (Extended DNS) options in ATLAS experiments. Researchers would like to test new or unspecified option values against DNS servers on the Internet, but this can lead to unexpected behaviour, even crashing DNS servers (if the DNS server software is not of high quality, which sometimes happens if network equipment vendors write their own implementations of DNS). There’s a risk in probing these EDNS options, but Christopher is not sure exactly how big the risk is.

IPv6-only

In the last lightning talk of Day One of RIPE 78, security expert Enno Rey presented his insights from an IPv6-only WLAN study that his company ERNW has conducted for a client. They found that mobile apps, especially on Apple’s iOS "just work.” (Which is no big surprise, as each app is tested by Apple to make sure it works as expected in an IPv6-only environment.)

ERNW found some applications that did not work out of the box and needed manual fixes, like the popular game "Fortnite" and its associated Epic Game Launcher. An XMPP (Jabber) component in the game only asked for IPv4 addresses (and the domain name has no IPv6 AAAA addresses), so this was naturally failing in a network without IPv4. Some other applications like Discord worked, but had some loss of functionality.

More tomorrow

This concludes our first report from RIPE 78. Check out our guide to both the event and the city, and stay tuned for more tomorrow.