Java SE "keytool error: java.lang.RuntimeException: java.io.IOException: DNSName components must begin with a letter" (Doc ID 2474036.1)

Last updated on MARCH 31, 2023

Applies to:

Java SE JDK and JRE - Version 7 and later
Information in this document applies to any platform.

Keytool does not recognize server names that begin with a number. It emits the following error when trying to generate a certificate:

However, since RFC 1123, the DNS naming convention requires allowing host names to begin with either a letter or number.

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In this Document

Symptoms

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