ifconfig information available

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Level 2

195 points

ifconfig information available

I have no problem, but I'm curious about the information available through ifconfig in terminal. When I input the command, I get the following result:

lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 16384
inet6 fe80::1%lo0 prefixlen 64 scopeid 0x1
inet 127.0.0.1 netmask 0xff000000
inet6 ::1 prefixlen 128
gif0: flags=8010<POINTOPOINT,MULTICAST> mtu 1280
stf0: flags=0 mtu 1280
en0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
ether 00:14:51:2b:4f:10
media: autoselect (none) status: inactive
supported media: none autoselect 10baseT/UTP <half-duplex> 10baseT/UTP <full-duplex> 10baseT/UTP <full-duplex,flow-control> 10baseT/UTP <full-duplex,hw-loopback> 100baseTX <half-duplex> 100baseTX <full-duplex> 100baseTX <full-duplex,flow-control> 100baseTX <full-duplex,hw-loopback> 1000baseT <full-duplex> 1000baseT <full-duplex,flow-control> 1000baseT <full-duplex,hw-loopback>
fw0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 4078
lladdr 00:14:51:ff:fe:2b:4f:10
media: autoselect <full-duplex> status: inactive
supported media: autoselect <full-duplex>
en1: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
inet6 fe80::214:51ff:fe7b:50eb%en1 prefixlen 64 scopeid 0x6
inet 10.0.1.2 netmask 0xffffff00 broadcast 10.0.1.255
ether 00:14:51:7b:50:eb
media: autoselect status: active
supported media: autoselect

I wondered if anyone might take a moment to explain all this to me. I don't mean everything; I'm primarily interested in understanding the local and external IP address and the MAC address as they are located in this jumble. Anything else important as well.

thank you

g5 iMac 17", Mac OS X (10.5.7), aex

Posted on May 24, 2009 5:19 AM

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Answer 1

Tim Haigh

Level 7

24,198 points

May 24, 2009 5:44 AM in response to homeshire

A good place to start is on the ifconfig man page.

Mac OS X Manual Page for ifconfig

en0 is your ethernet port
en1 is your airport port

so in your ifonfig results I see that you are connected using airport and your IP address is
IP 10.0.1.2 subnet 10.0.1.255

Your airport MAC address is 00:14:51:7b:50:eb

Your public IP address is not displayed as your public IP address is on your router.

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Answer 2

homeshire Author

Level 2

195 points

May 24, 2009 5:52 AM in response to Tim Haigh

Thanks for responding Tim --

a few questions. I get all that you've pointed out. When you say my public IP address is not displayed, do you mean the one that looks like 192.102.14.102?

Also, my point in asking at all is that i had the thought i might use ssh to log into my parents computer for troubleshooting purposes, as it drives me crazy to try to help over the phone. What information might I use from all this to use ssh?

thanks
homeshire

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Answer 3

Tim Haigh

Level 7

24,198 points

May 24, 2009 6:04 AM in response to homeshire

192.102.14.102

That is an internal IP address not a public IP.

Your public IP address is the one you see when you goto http://whatismyip.com

As your EN1 ip address is 10.x.x.x. this suggests that you are connected to an apple airport base station.

If you are expecting to see a 192.x.x.x address. This suggests that also have a modem/router.

Can you please describe your full network setup?

Also, my point in asking at all is that i had the thought i might use ssh to log into my parents computer for troubleshooting purposes, as it drives me crazy to try to help over the phone. What information might I use from all this to use ssh?

I hear you.

First thing I did was purchase my Mum a mac mini a few years back and setup SSH.

but describe the full seutp and then we can get SSH working.

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Answer 4

homeshire Author

Level 2

195 points

May 24, 2009 6:46 AM in response to Tim Haigh

Thanks Tim --

the external ip address I offered was made up, not real. the 192 suggests I have a wireless connection within my house, but no connection to the outside world (at least that is my understanding). Just to be safe, I made that up, as I'm never quite sure what information I can offer to the public, and what I should keep hidden. I used the link you offered to confirm my suspicion that my external ip address was what I thought. thank you. As well, that looks like a useful site and is now bookmarked.

As far as ssh is concerned, I wonder if I'm looking at a bazooka to kill a gnat. I'm trying to learn a little about it so that I might play with it. But all I want to do is be able to work on my parents eMac running tiger rather than listen to her largely meaningless attempts to explain to me what the problem is over the phone. I know I want to be able to remotely log in, and ssh is what comes to mind. But I am open to being educated on this.

As I said, she has an eMac running tiger, and as you can see below, i am running leopard. How would I best proceed?

Thanks Tim

homeshire

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Answer 5

Tim Haigh

Level 7

24,198 points

May 24, 2009 7:03 AM in response to homeshire

OK, I understand.

regarding your ssh connection to your parents house.

You need to configure your parents mac with a fixed local IP address. then configure their router to forward tcp port 22 to the IP address of the emac.

You would need an account on their emac.

It is unlikely that your parents ISP give them a static public IP address so you need to look into http://dyndns.com

a dynamic domain name will update every time your parents IP address changes.

So you would register something like parentsemac.dyndns.org

it is free.

Then you install a dydns client on the emac or there may be a dyndns client inside their router.

Once all that is done, install Vine Server on the emac, configure it as as startup item. use port 5900

Then using ssh you can create a tunnel

ssh -L 5901:localhost:5900 parentsemac.dyndns.org

Then using a vnc client such as jollysfast vnc client

you could connect from your mac at home using the vnc client and a server address of localhost:5901

Then you would have control of their screen.

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Answer 6

homeshire Author

Level 2

195 points

May 24, 2009 7:40 AM in response to Tim Haigh

Thanks so much Tim --

However, that's quite a load and will take some time.

It's sunday and my wife is on me to go somewhere with the kids and her. So please understand it may be some days before I post back saying mission accomplished.

In any event, thanks for your time and effort. It serves to remind me of the value of these forums.

best regards

homeshire

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