<p>This seems to be an issue of nslookup there ... on a recent RHEL:</p>

<p>rhel5:~/monitoring-plugins<br>
[0]markus [PR681] $ cat /etc/redhat-release <br>
Red Hat Enterprise Linux Server release 5.10 (Tikanga)</p>

<p>rhel5:~/monitoring-plugins<br>
[0]markus [PR681] $ nslookup <a href="http://www.rm.com">www.rm.com</a> 1.1.1.1<br>
;; connection timed out; trying next origin<br>
;; connection timed out; no servers could be reached</p>

<p style="font-size:small;-webkit-text-size-adjust:none;color:#666;">—<br><a href="https://github.com/monitoring-plugins/monitoring-plugins/issues/982#issuecomment-50593983">Reply to this email on GitHub</a>.<img alt="" height="1" src="https://github.com/notifications/beacon/5514713__eyJzY29wZSI6Ik5ld3NpZXM6QmVhY29uIiwiZXhwaXJlcyI6MTcyMjMzMjM5NiwiZGF0YSI6eyJpZCI6MTcyNzc1ODh9fQ==--9214784dd9714585d8176e34758e03770d495cbf.gif" width="1" /></p>