for use with Hubs (half-duplex ONLY)

• the most simple one... just rx-only
• rx-only, but try to pacify hub's "link status" checking by sending junk back to the hub
• use one hub port to simulate transmission to another port on the same hub
• a switch's span port can be used to sniff all data?
• this worked very well for me on my cable modem...
  • cable modems in the US are typically capped at 3mbps down and 256kbps up, so even a half-duplex 10-base-T hub has very little collisions with this
  • costs about $30 new, and is probably nearly guaranteed to work
  • boot knoppix on a laptop, and it's magic...
  • ifconfig eth0 up
  • SIP tcpdump filter: udp port 5060
  • on windows...
    • ip = 0.0.0.0?
    • simply ipconfig /release "Local Area Connection 3"?

for use in the middle of a cat5

• Passive Ethernet Tap — setting up two NICs to listen to each half of a full-duplex ethernet cable
• combining both halves into a single NIC, by using an ethernet switch (bizarre)
• mentions why a 2-NIC Tap is preferable to even a span-port (basically, it won't lose packets when both halves are going full-steam)
• construction:
  • soldering/twisting is probably right out
  • punch-down style stuff are THE way to go
  • 110 punch-down blocks are best for 100mbps
  • you don't really need an actual punch-down tool
  • go to Home Depot. Buy two Leviton cat5 jacks. Insert them in the middle of your existing cat-5 cable. Connect to switch via two patch-cables. Voila, simple.
  • complete how-to on the HomeDepot solution.
  • alternatively, order two keystone cat5e jacks and a 2-port biscuit which you thread a long cat5e cable through