How four rotten packets broke CenturyLink's network for 37 hours, knackering 911 calls, VoIP, broadband
A handful of bad network packets triggered a massive chain reaction that crippled the entire network of US telco CenturyLink for roughly a day and a half.
This is according to the FCC's official probe [PDF] into the December 2018 super-outage, during which CenturyLink's broadband internet and VoIP services fell over and stayed down for a total of 37 hours. This meant subscribers couldn't, among other things, call 911 over VoIP at the time – which is a violation of FCC rules, and triggered a formal investigation....
We're told four malformed network packets were the root cause of the outage: they were generated by a switching module in a node in Denver, Colorado, for reasons still yet unknown, and sent on to other nodes. The broken packets all had the following qualities:
1. a broadcast destination address, meaning that the packet was directed to be sent to all connected devices;
2. a valid header and valid checksum;
3. no expiration time, meaning that the packet would not be dropped for being created too long ago; and
4. a size larger than 64 bytes.
https://www.theregister.co.uk/2019/08/20/centurylink_outage_report_fcc/
Note: Already posted by Hellfire in a DSLR software forum.
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