“To be honest, it was only a small background. “From what I saw, there was no mail server in that small domain, which was used for Azure services,” said Caturegli. “[But] as the end user, you have no idea where you are going. You simply trust DNS. “
The problem is that this type of cut-and-paste error is very easy to make, and the nature of strings makes it difficult to spot the error. Even worse, if it’s a mistake not received immediately, it can last longer, as Mastercard has learned.
“You have to constantly check your settings for obvious mistakes. But with DNS, once it’s fixed, it won’t make a mistake,” said Caturegli. “Unless you check your configuration, you won’t know about this issue. You can’t rely on tools. They wouldn’t even have logs (to show the error). They won’t see it in any of their logs.”
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