Can I obtain Mac Address of other Macs on my home network...?
 

Hi All

I want to be able to control availability of internet access on some Macs on my home network. I appreciate I can go to the Mac and obtain the Mac Address from Airport Utility, but am I able to get the Mac Address for a machine when they are actually connected to the home network...?

Is this possible...?

Ta

you should be able to find the MAC addresses of all connected devices somewhere in the configuration interface for your router...

Hmmmm, I have looked but I can't see them. I have the Apple Airport Extreme router, any ideas?

oh yeah, the AEBS is a pain like that... i wonder if there is some hidden way of finding that info from the Airport Utility?

someone with better networking chops than me may well chime in with a better way to do this, but here are a couple of ways i can think of right now:

you can use the Network Utility (use the Netstat tab to display the routing table information)...

a more user-friendly way is to use the IP Scanner app from 10base-t
http://10base-t.com/macintosh-software/ip-scanner/

I'm not sure this is what you mean, but you can see the MAC addresses of all machines (Mac or not) that are connected wirelessly to your Airport base station in the "Wireless Clients" tab of the page you get via the "Logs and Statistics" button in the "Advanced" section of Airport Admin utility.

i'm using Airport Utility 5.3.2, and i can't find a "Wireless Clients" tab anywhere...

Do you have an "Advanced" section in your Airport Utility?
(My Airport Utility is also version 5.3.2. I'm using OS X 10.5.6. My base station is a Time Capsule.)

This probably won't help in this case, but you can see the MACs of every machine that your machine can see directly (hub style rather than switch) by doing "arp -a" in a Terminal.

In the case of a switched network, you will just see the router(s), which isn't very useful.

WakeOnLan probably shows all those MAC addresses in its list.

This isn't true.

If you're machine has communicated with any other host on the local segment, there will be an entry for it in the arp table.

One quick way to 'warm up' the arp table is to issue a ping to the entire network, but this assumes that the other hosts will actually reply to ICMP echo requests.

Here's an alternate route to what hayne suggested.

Open Airport Utility and double-click on the left-side icon for the Airport Extreme.

In the summary that opens, click on the words "Wireless Clients." You'll see a list of every MAC address on your network in the window that opens.

weird, i'm on 10.5.6 too, but with an Airport Extreme... ah, maybe Airport Utility is behaving differently because my AEBS is in bridge mode?

If your AEBS is in bridge mode, go to your actual router to check for the MAC addresses of all connected devices.

Trevor

ta, that's what i do (i've put most of my equipment on static local addresses)...

i rarely use my AEBS wirelessly, so i didn't realise that Airport Utility wouldn't show all the wireless clients when in bridge mode, which seems a bit odd, and not very handy when you are setting up MAC access control...

You didn't answer my question, so I ask it again:

Do you have an "Advanced" section in your Airport Utility?
(see below screenshot from top of my Airport Utility window)

Does MAC access control even work when you are in bridge mode? It isn't obvious that it does. (I mean in theory - I haven't tried it. The idea of bridge mode is basically to transparently hand all packets over to the other router.)

Oh, I hadn't noticed that all of this effort was for MAC access control? Don't put any effort at all into that, it has no security benefits at all. Script kiddies with no knowledge of their own can break a network with MAC access control just as quickly as they can break a network without it.

Use real security (like WPA2 encryption for wireless networks), not fake placebo sugarpill security like MAC access control.

Trevor

well the OP is simply wanting to use MAC access on his home network, which is fair enough, shortcomings noted...

personally i use WPA2 as well, with a ridiculously long passphrase...

for completeness:
@Hayne: yes my Airport Utility has an Advanced tab, and a Log & Stats button, but there is no Wireless Clients tab/button... yes i can see all the MAC addresses by sifting through the log, but it isn't very user friendly... my machine is the currently the only one connected wirelessly, maybe that is why? i tried taking my AEBS out of bridge mode, but still no Wireless Clients display... and i've just noticed that there is a "Wireless Clients" entry in the Summary tab of the Airport pane, but it just shows a "-" when mine is the only machine connected wirelessly (i don't have another machine to try today)...

oh, and yes, MAC access control does work in bridge mode (just tested it)...

now i really want to know why i can't see the wireless clients directly in my Airport Utility!

So the top of the pane that you get when you click on the "Logs and Statistics" button doesn't look like the screenshot below?
(I also have only one wireless client connected to my Time Capsule at the moment and it shows up in the Wireless Clients tab of the Logs and Statistics pane.)

nope, i only have Logs...

Something else might be askew. I set my Airport Extreme Base Station to Bridge Mode and I was able to see the Wireless Clients tab showing the MAC addresses for my MacBook Pro, Airport Express and iPhone.

WHOOPS!

i had SNMP turned off!

i can sleep again at night, haha

Do you have "Allow SNMP" checked in the "Advanced" tab ?
(screenshot below)
[edit]
I see that you just replied saying that you had it off
[/edit]

hehe, now that's a boo boo i'll never make again...

it is stupid that you can't copy a MAC address from the Wireless Client's list though...

In the Wireless Clients tab, using Edit->Copy (or Command-C) will copy the MAC address.

mmm, i should sleep more before i open my mouth again today...