Cloudfare explains why Facebook disappeared from the internet
- Social networks
Cloudfare has possibly the most sensible answer to why Facebook and its derivatives (Instagram and WhatsApp ) have been offline since 16:51 (UTC) this Monday, October 4.
One of the simplest explanations is that it was as if someone had “pulled the wires” out of their data centers and disconnected them from the internet, since DNS was unresponsive and infrastructure IPs were inaccessible.
The key to BGP
For Cloudfare, an American web infrastructure and website security company that provides DDoS mitigation services and content delivery networks, the key is in BGP, but is it? what is this?.
The explanation is as follows:
“BGP, Border Gateway Protocol, is a mechanism for exchanging routing information between autonomous systems (AS) on the Internet. The big routers that make the internet work have huge, constantly updated lists of possible routes that can be used to deliver each network packet to its final destinations. Without BGP, the internet routers wouldn't know what to do and the internet wouldn't work. The Internet is literally a network of networks and is linked by BGP, which allows a network (say Facebook) to announce its presence to other networks that make up the web. As we write, Facebook is not advertising its presence, ISPs and other networks cannot find the Facebook network and therefore it is not available. Each of the individual networks has an ASN, an autonomous system number. An AS is an individual network with a unified internal routing policy; it can originate prefixes (let's say they control a group of IP addresses), as well as transit prefixes (they know how to reach specific groups of IP addresses)”, Cloudfare details very precisely.
Cloudfare acknowledges that at 16:58 (UTC) Facebook stopped advertising the routes to their DNS prefixes, therefore they had been disconnected from the internet.
This not only caused external communications with users to fail, but also the employees themselves recognized internal communication connection errors and even not being able to access the institutional buildings of Zuckerberg's company.
Cloudfare's conclusion: “Because Facebook stopped advertising its DNS prefix routes through BGP, our and everyone else's DNS resolvers had no way to connect to their nameservers. Consequently, 1.1.1.1, 8.8.8.8, and other major public DNS resolvers began issuing (and caching) SERVFAIL responses."
In addition, the fact that many people try to access the systems, by reloading Facebook, Instagram and WhatsApp pages and applications, further slows down the recovery.
