What is en0, en1?

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Level 1

9 points

What is en0, en1?

I don't have the background to understand what the interface designations en0 and en1 are referring to. My concern is that my hard drive just went through about 2-3 minutes of activity. Don't know if it was normal housecleaning going on but found a system log file with several of these messages (Mar 16 22:28:18 p****-a***-power-mac-g5 ipfw: 35000 Deny UDP {IP Address}2190 {IP Address}:2190 in via en0). Am I to interpret someone was trying to enter my system or has entered my system? Advice on where to go to learn and figure this out will be appreciated. Thanks!

G5, Mac OS X (10.4.11)

Posted on Mar 16, 2008 10:59 PM

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Answer 1

BDAqua

Level 10

251,171 points

Mar 17, 2008 1:42 AM in response to PDA2

Hi & a warm welcome to the forums! 🙂

en0, en1 etc are BSD names for the ports...

http://www.macosxhints.com/article.php?story=20051020014120761

Generally named as they are initiated on startup, 1st en0 is normally Ethernet, en1 normally Airport, but some computers will have more ethernet Ports end Airport moved up to en2, en3 etc..

Those look like attempts to get in, most likely means you don't have a router and are connected to a Modem and have an outside IP. I see 1000s a day even on dialup. It can also be inside your own network... depending on the IP, for instance TiVo can use port 2190.

You can put those IP numbers in Network Utility>Lookup tab and see if what they belong to.

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Answer 2

PDA2 Author

Level 1

9 points

Mar 17, 2008 6:42 PM in response to BDAqua

Thank you for your assistance. The article answered my questions. I do have a router and Tivo and have a firewall and password but will need to figure out whether or not my security has been breached.

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Answer 3

BDAqua

Level 10

251,171 points

Mar 17, 2008 6:47 PM in response to PDA2

I do have a router and Tivo and have a firewall and password but will need to figure out whether or not my security has been breached.

I'd say no, from your info, but should you want more tools to be certain...

ClamXAV, free Virus scanner...
http://www.clamxav.com/

Little Snitch, stops/alerts outgoing stuff...
http://www.obdev.at/products/littlesnitch/index.html

HenWen/Snort combo, that is a free MAJOR Firewall...
http://seiryu.home.comcast.net/henwen.html

Then the venerable old Brickhoues/Flying Buttress Firewall...
http://personalpages.tds.net/~brian_hill/downloads.html

WaterRoof is a firewall management frontend with bandwidth tuning, NAT setup, port redirection, dynamic rules tracking, predefined rule sets, wizard, logs, statistics and other features.
http://www.macupdate.com/info.php/id/23317

Monitor net usage...
http://mac.softpedia.com/get/Dashboard-Widgets/Information/Videotron-Internet-Us age-Monitor.shtml

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