Where can i find the LinkManager Sniffer tool?

This article will help answer this commonly asked question

The latest LinkManager does not include the Sniffer as you know it from the previous version of LinkManager.
A future release of LinkManager may include a similar tool.

For now, we recommend that you use the tool RawCap (http://www.netresec.com/?page=RawCap) to capture packets for troubleshooting purposes.