Some cases where "rdns = false" in krb5.conf does not work in Hadoop ecosystem
https://web.mit.edu/kerberos/krb5-1.13/doc/admin/princ_dns.html Operating system bugs may prevent a setting of rdns = false from disabling reverse DNS lookup. Some versions of GNU libc have a bug in getaddrinfo() that cause them to look up PTR records even when not required. MIT Kerberos releases krb5-1.10.2 and newer have a workaround for this problem, as does the krb5-1.9.x series as of release krb5-1.9.4. There are some cases where “rdns = false” in krb5.conf is not respected in Hadoop ecosystem. You can try to modify /etc/hosts or register PTR records to fix this kind of issues. ...