I am able to download the cmode simulator.It took me around 30mins approx (depends on the bandwidth and download speed)
I am not sure why the download is not working for you. May be the download is getting disconnected. Are you using any download managers ? or direct browser download.
I would suggest you to use the feedback link in the bottom of the page for http://support.netapp.com/NOW/download/tools/simulator/ontap/8.X/ to report download problems