Passive Lan Tap Challenge

[Infatuas]

I recently was looking to purchase the throwing star LAN tap for some professional uses for troubleshooting VoIP issues. I currently will just configure port mirroring within a managed switch of some variety; which is entirely functional but not always practical. I decided to build my own little LAN Tap Box for fun using these schematics. It works perfect fine but as expected the Tap ports will watch only the TX or RX but not both simultaneously. If was to theoretically bridge pairs 3 & 6 on both Tap jacks it would in essence combine TX and Rx and break the functionality of the hosts altogether.

I am not ready to give up on this yet, but is there tested or even logical method to have a single Tap jack listen to both TX/RX between two hosts? I know hubs/switches can do this already but I'd like to build one.

Attempts so far:

1. Above schematic (works but TXly tRxor rx depending on which tap port your listening on, expected)

2. 3 RJ45 Jacks creating a half circle linking all pars together with a single strand per port. (does not work, drops the hosts connection and listening device)

I was also thinking that if you can use a Cat5e splitter like this, Cable Splitter; then it has to be do-able.

Thanks,

Infatuas

[Mr-Protocol]

It won't work like that. Even the professional equipment has TX monitor and RX monitor.

Multimode Fiber Taps I have:

Copper Tap:

Don't ask how/where I got these :P but I'd be willing to sell 1 of each :) hehe

Edited December 8, 2011 by Mr-Protocol

[digip]

Easiest way is purchase an old hub, sees everything, transmit and receive, but will also fubar the network speeds. If only in, out and one other machine for monitoring, on a small network wont be noticed.Other than that, standard lan tap, or port mirroring. With no hardware, ARP MITM attack, but thats neither passive or reliable for long periods of time without causing traffic issues on the network.

[Infatuas]

Well, it was worth a shot. Typically, I use a HP Procurve Switch and just port mirror to my laptop so I get both in and out that way, but it's almost always short term troubleshooting. I do like the copper taps Mr-Protocol! I'm thinking of just buying a usb to ethernet adapter and attempting to bridge two ethernet connections for both tap ports in Ubuntu. That would do the trick.

Thanks!

[Mr-Protocol]

Make sure the USB Adapter is able to work with linux, most I've seen are Windows only.

[Infatuas]

Well then, this should help: http://free-electrons.com/blog/usbeth/

[httpCRASH]

Well, it was worth a shot. Typically, I use a HP Procurve Switch and just port mirror to my laptop so I get both in and out that way, but it's almost always short term troubleshooting. I do like the copper taps Mr-Protocol! I'm thinking of just buying a usb to ethernet adapter and attempting to bridge two ethernet connections for both tap ports in Ubuntu. That would do the trick.

Thanks!

if you just need ethernet to USB, then i can recomend theese http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=170735483163

got a couple of them, and they work out of the box with backtrack (and im sure other linux distros too)

im using one when doing ICS to my pineapple, to connect both pineapple and lan to my laptop..