Post #760722

2024-05-23 17:26 UTC

For more than four days, a server at the very core of the Internet’s domain name system was out of sync with its 12 root server peers due to an unexplained glitch that could have caused stability and security problems worldwide. This server, maintained by Internet carrier Cogent Communications, is one of the 13 root servers that provision the Internet’s root zone, which sits at the top of the hierarchical distributed database known as the domain name system, or DNS. Given the crucial role a root server provides in ensuring one device can find any other device on the Internet, there are 13 of root servers geographically dispersed all over the world. Normally, the 13 root servers—each operated by a different entity—march in lockstep. When a change is made to the contents they host, it generally occurs on all of them within a few seconds or minutes at most. Strange events at the C-root name server This tight synchronization is crucial for ensuring stability. If one root server directs traffic lookups to one intermediate server and another root server sends lookups to a different intermediate server, the Internet as we know it could collapse. More important still, root servers store the cryptographic keys necessary to authenticate some of intermediate servers under a mechanism known as DNSSEC. If keys aren’t identical across all 13 root servers, there’s an increased risk of attacks such as DNS cache poisoning. For reasons that remain unclear outside of Cogent—which declined to comment for this post—the c-root it’s responsible for maintaining suddenly stopped updating on Saturday. Stéphane Bortzmeyer, a French engineer who was among the first to flag the problem in a Tuesday post, noted then that the c-root was three days behind the rest of the root servers. https://arstechnica.com/security/2024/05/dns-glitch-that-threatened-internet-stability-fixed-cause-remains-unclear/

Replies (8)

@jima@mspsocial.net 2024-05-23 17:44

@dangoodin @bert_hubert It might be worth noting that each root "server" is actually between 6 and 345 distinct instances — but from what I've read so far, all 12 of Cogent's were impacted in the same fashion. https://root-servers.org

Open ##1253113
@kithrup@wandering.shop 2024-05-23 19:24

@dangoodin Slight nit, there are many, many f's around the world.

Open ##1253114
@markd@hachyderm.io 2024-05-23 21:23

@dangoodin "the Internet as we know it could collapse" might be a slight over-dramatisation. - #DNS roots are massively anycast so mostly only Cogent's customers and peers are affected. - root responses are cached for days so the internet is *always* out of sync - by design! - Update delays and caching implications are routinely monitored by dns operators which is why this was noticed. - Many significant domains (apple.com, au.) haven't changed in years, so unaffected.

Open ##1253115
@grumpybozo@toad.social 2024-05-23 22:24

@dangoodin @CliftonR My money is on some fraction of the Indians who can’t connect normally to many places in the US because of the Tata/Cogent spat having skillz & malice in their hearts… It was suggested somewhere public (NANOG?) recently that Cogent’s peering practices should threaten their operation of C-Root. (NOTE: I DO NOT AGREE)

Open ##1253118
@wargreen@mastodon.tetaneutral.net 2024-05-23 23:04

@dangoodin Loool, 6 days before, a congent DC have some water inside... With our server inside the DC... Lot of services was down. It will be very fun if some relation exist... !

Open ##1253120
@aardvark@ioc.exchange 2024-05-24 00:09

@dangoodin https://www.wired.com/2012/10/joe-postel/ (sic; wow, how did Wired botch that URL so badly?)

Open ##1253122
@noplasticshower@zirk.us 2024-05-24 00:31

@dangoodin le time she is behind

Open ##1253123
@bluknight@dotorg.org 2024-05-24 12:07

@dangoodin going on a little rant here, please bear with. If I remember (and did a cursory search correctly, and @joeklein keep me honest here) Cogent is still refusing to peer IPv6 with Hurricane Electric without a paid relationship. Cogent and HE are two very large transport providers, especially in v6 space. (more)

Open ##1253124