JMeter and Amazon Elastic Load Balancer (ELB) Issues The ELB is a name, not IP, and can suffer from DNS caching. Make sure you use "-Dsun.net.inetaddr.ttl=0" when starting JMeter For a description of how the ELB works, see http://www.shlomoswidler.com/2009/07/elastic-in-elastic-load-balancing-elb.html, but if the link is down or you just need a high level overview: Because the ELB is a DNS name, A