Anyone know where I can get my hands on a network tap in the GVRD? Doesn’t have to be anything too special, this isn’t a crazy fast line.
I think I’ve discovered that I’ve been owned and I want to check that my router isn’t up to any funny business as well.
what do you mean by “network tap” ? like a physical wire splitter, or a linux box running tcpdump, or like, a jack in the wall to plug into for “internet” access?
edit:
this is a read-only ethernet cable, used to mirror one direction of a layer-2 ethernet session to a second network port:
EDIT: Sorry
I was looking for that except something more pluggy pluggy but that sounds like it will achieve the goal if I can find some spare cables.
you could use the female keystone jack connectors instead, and build this into a 4-port surface mount box, like these: ,https://cdn11.bigcommerce.com/s-u2tggdqa5v/images/stencil/1280x1280/products/36/3143/IMG_2944_copy__27169.1499383842.jpg
I probably would anyway, because soldering on cat5 wires can really tank the SNR of the cable, whereas you could build the other in 5 minutes with a punchdown tool and 12" of cat5 solid core.
You’d have to be on the outside network edge of the router if you don’t trust the router, so if it’s ALSO your modem (ADSL/Fiber/Cable), then it’s a lot harder as a problem.
If you want a cheap enough way to do it otherwise, just grab a network switch that supports monitor/capture ports. Have a VLAN that just passes traffic between your modem & router, and also copies all traffic off the VLAN onto a monitor port that you can dump for analysis.
I have a little NetGear GS108Ev2 that I’ve used in the field for this explicit purpose, the only downside was having to use a Windows Vista VM to configure it in the first place. No VLAN, just dump all of ports 1-4 to port 8. Ports 5-7 pass traffic but don’t dump.
Thank you so much both of you. Good tips. I was planning to put it right between the modem and router.
Where do you shop for such components?
or
Where should I go to get the tool and whatnot?
So, what you want is actually just an old hub… Or…
THE THROWING STAR LAN TAP!
https://greatscottgadgets.com/throwingstar/
I have one. You can borrow it if you’d like. You’ll want USB network cards to monitor the traffic.
I was actually exactly thinking of the throwing star tap but I don’t have one and I wanted to deal with this sooner than I think I could get it shipped. And that being the case, I think I might avail myself of your offer.
Why would I need a USB NIC specifically? Do I need 2 because duplex?
You need two as each “side” of the tap reads one. Doesn’t need to be USB, anything with two networks.
I am heading out of town tonight, and won’t be back until tuesday, unfortunately. but I can bring it to VHS then.
That’d be good I should be in on Tuesday. If I get it sorted before I’ll let you know. Thanks again.
Question for all of you:
If I have two NICs anyway and I’m not worried about reliability of the link couldn’t I invisibly MITM that traffic somehow? If so do you know how? My searchfoo is failing me.
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