Weird mail problems today? Clear your DNS cache!

A number of sources are reporting this morning that there was a problem with some domains in the .com zone yesterday. These problems caused the DNS records of these domains to become corrupted. The records are now fixed. Some of the domains, however, had long TTLs. If a recursive resolver pulled the corrupted records, it could take up to 2 days for the new records to naturally age out.
Folks can fix this by flushing their DNS cache, thus forcing the recursive resolver to pull the uncorrupted records.
EDIT: Cisco has published some more information about the problem. ‘Hijacking’ of DNS Records from Network Solutions

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This traffic is so massive, that it’s actually affecting the Internet and web surfers in some parts of the world are seeing network slowdown because of this.
While I know that some of you may be cheering at the idea that Spamhaus is “paying” for their actions, this does not put you on the side of the good. Spamhaus’ actions are legal. The actions of the attackers are clearly illegal. Not only is the attack itself illegal, but many of the sites hosted by the purported source of the attacks provide criminal services.
By cheering for and supporting the attackers, you are supporting criminals.
Anyone who thinks that an appropriate response to a Spamhaus listing is an attack on the very structure of the Internet is one of the bad guys.
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Here are some resources for the technical folks.
Open Resolver Project
Closing your resolver by Team Cymru
BCP 38 from the IETF
Ratelimiting DNS
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NY Times
BBC News
Cloudflare update
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Cyberattack on anti-spam group Spamhaus has ripple effects
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