Snort mailing list archives
Re: Passive Tap Help
From: Jeff Nathan <jeff () snort org>
Date: Mon, 1 Dec 2003 12:47:35 -0500
counter.spy () gmx de once sent this to me... it might help you out. (Attached) -Jeff
On Dec 1, 2003, at 11:17 AM, kenw () kmsi net wrote:
On Mon, 1 Dec 2003 10:21:53 -0500, you wrote:http://www.snort.org/docs/100Mb_tapping1.pdf is the picture I amreferencing. I am looking to decipher the exact pin out of the 100Mb coppertap. It looks like I would have 4 - RJ45 Ethernet jacks in the tap.Yup.I guess I am looking for an "Ethernet Tap for Dummies" version that includesthe wiring pin out for all 4 jacks. Best regards, Michael D. PetersThat diagram is interesting. Essentially, what it does is take both sidesof a Cat 5 cable and feed them into separate RX lines on two ports of aswitch, and then use the switch's spanned port to "see" them both at once.Pin numbers on it could have helped, but you can look at any Ethernet RJ45pinout diagram for them. I recommend it for educational value. Just remember to match polarities.Note that the "copper tap" may appear to constitute a crossover connection on the full duplex lines, but it doesn't. TX stays TX, RX stays RX. Thecrossover occurs when one FDX TX line goes the a switch's RX lines.You could even build a box with no crossovers at all, and use a crossovercable on one of the switch ports. So far as I can see, this is a lot of trouble and expense (low-costswitches with port spannning are rare) to go to when you could do nearly all of it with a cheap hub. The tap's claim to fame is that it passes fullduplex while monitoring both ways, by funneling two Ethernet lines intoone; it relies on the spanned port's buffering to avoid dropping packets. A hub would accomplish the same net result by disabling full-duplex on the tapped line, but that's usually a minor issue, very unlikely to be noticedon all but the busiest links. /kenw Ken Wallewein CDP,CNE,MCSE,CCA,CCNA K&M Systems Integration Phone (403)274-7848 Fax (403)275-4535 kenw () kmsi net www.kmsi.net ------------------------------------------------------- This SF.net email is sponsored by: SF.net Giveback Program. Does SourceForge.net help you be more productive? Does it help you create better code? SHARE THE LOVE, and help us help YOU! Click Here: http://sourceforge.net/donate/ _______________________________________________ Snort-users mailing list Snort-users () lists sourceforge net Go to this URL to change user options or unsubscribe: https://lists.sourceforge.net/lists/listinfo/snort-users Snort-users list archive: http://www.geocrawler.com/redir-sf.php3?list=snort-users
-- http://cerberus.sourcefire.com/~jeff (gpg/pgp key id 6923D3FD) "Problems cannot be solved at the same level of awareness that created them." - Albert Einstein
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Current thread:
- RE: Passive Tap Help, (continued)
- RE: Passive Tap Help Lists (Dec 01)
- RE: Passive Tap Help Frank Knobbe (Dec 01)
- RE: Passive Tap Help Frank Knobbe (Dec 01)
- RE: Passive Tap Help Lists (Dec 01)
- RE: Passive Tap Help Frank Knobbe (Dec 01)
- RE: Passive Tap Help Frank Knobbe (Dec 01)
- RE: Passive Tap Help Dirk Geschke (Dec 01)
- RE: Passive Tap Help Frank Knobbe (Dec 01)
- RE: Passive Tap Help Frank Knobbe (Dec 03)
- Re: Passive Tap Help Jeff Nathan (Dec 01)
- Re: Passive Tap Help Frank Knobbe (Dec 01)
- Re: Passive Tap Help Jeff Nathan (Dec 02)