Meine aktuelle Paketempfehlung für Debian basierte Linux-Distributionen:

$ apt-cache show dsniff
  :
Description: Various tools to sniff network traffic for cleartext insecurities
 This package contains several tools to listen to and create network traffic:

  * arpspoof  - Send out unrequested (and possibly forged) arp replies.
  * dnsspoof  - forge replies to arbitrary DNS address / pointer queries
                on the Local Area Network.
  * dsniff    - password sniffer for several protocols.
  * filesnarf - saves selected files sniffed from NFS traffic.
  * macof     - flood the local network with random MAC addresses.
  * mailsnarf - sniffs mail on the LAN and stores it in mbox format.
  * msgsnarf  - record selected messages from different Instant Messengers.
  * sshmitm   - SSH monkey-in-the-middle. proxies and sniffs SSH traffic.
  * sshow     - SSH traffic analyser.
  * tcpkill   - kills specified in-progress TCP connections.
  * tcpnice   - slow down specified TCP connections via "active"
                traffic shaping.
  * urlsnarf  - output selected URLs sniffed from HTTP traffic in CLF.
  * webmitm   - HTTP / HTTPS monkey-in-the-middle. transparently proxies.
  * webspy    - sends URLs sniffed from a client to your local browser
                (requires libx11-6 installed).