How do I find out who is connected to my airport extreme?

Question

I have a motorola WPS870G wireless printserver that has an old HP LJ4 attached via parallel. I had a netgear router and all was good. I had it set up so that the router always assigned the same IP address to the print-server, and then I had my G4 set up to print to that IP address - then shared the printer to my MBP along with the other two printers attached to the G4 which is really now just a server in the closet. Anyway, when I switched over, I can't figure out how to find what IP address is being assigned to the printserver now nor how to make sure it's fixed. I've logged onto the printserver and set it to ask for the same IP address every time from the extreme and it does show that it's connected (based on the lights that are lit). I should also share that I first had to change the network SSID and the WEP pw to match the new network. I first tested to make sure it disconnected from the old network, then made sure the lights came back on for the new network. But now I cant figure out what IP address it's connected to. Ultimately, I need to be able to hard code that into the shared printer on the G4 to get everything back in working order. Any suggestions on how to get this printer working?
Thanks.

Answer 1

I'm not sure if this is what you're looking for, but you can find out who's connected by using something like Airport Monitor Utility (3rd party software) or you can use Apple's Airport Utility. Apple's Utility will also let you change settings if you don't like what you find, so we'll use that for this little example.. Please read through this whole thing before you attempt it so you know what to expect at each part and how it relates to later information. Note this will only work if the parallel print-server is connected directly to the AirPort router by wireless or wired connections. If there are any in-between routers, these directions may fail to help you and you should consider reconnecting the print-server directly to the AirPort base station.
First, write down the MAC address of the print server (or ANY other device) you need to configure for a "static" address. In this case, I mean static address not by the sense that we are not using DHCP to assign it, but in the sense that ultimately it doesn't change so your Macs and other computers/devices can always find it on the network.
* If you can't find the MAC address of the print-server or other device in question, then the only other way to go about assigning it a non-changing address will require that you can access that devices internal network setup configurations (some helpful directions on that at the bottom of this text) and set the device's DHCP Client ID to something that you will set the Airport to look for later when it assigns the print-server its connection address. MAC Address is probably easiest to use because you may be able to find the MAC Address of the device on a sticker on its case. If you can't see a MAC Address listed on the device or it has been altered through settings and you can't access the device's setup configuration pages over the network to find its current Mac Address, you may still be able to figure it's MAC Address out by following the monitoring directions immediately below.
Using Airport Utility v5.3.2, here are directions for monitoring and assigning addresses, etc:
* How to see who's connected....
1. Open Airport Utility.app
2. Select the appropriate Airport base station.
3. Click "Manual Setup" at the bottom.
It will read settings for a moment, then you should see info on the station itself. If not, click the Airport logo on the left side of the top bar of icons to take you back to this top menu page and click the "Summary" sub-tab on the left below it.
NOTE: A lot of people don't realize the fact that this "info" is actually a menu with hidden shortcuts that lead to a lot of advanced useful features that otherwise you might take a while to hunt down navigating icons and tabs above. You have to actually mouse over each line to figure that out.
4. To find out who's connected, mouse-over the entry that says Wireless Clients until it has a right-pointing arrow in a circle appear to alert you that it's now a link. Clicking "Wireless Clients" will be a shortcut that saves you a lot of time and clicking that would equate to clicking the obvious controls above in the order: icon "Advanced", then tab "Logging", then page link "Logs and Statistics" then tab "Wireless Clients".
Note: This info is not a static display, but an active charting of who's connected, at what speeds, with what signal to noise ratios. It updates very quickly.
5. From here, you can click the "DHCP Clients" tab to see all the devices connected to this basestation by either wireless or wired connections and their relevant MAC addresses, etc. This page unfortunately has no direct quickly like its neighboring tab for Wireless clients, but at least you have a shortcut now to get you to this pages nearest neighboring tab which does save some time.
Note: This info will be helpful to figure out what's going on with your print-server or other routers/devices if you know their MAC addresses. You can find the MAC address on most devices on a sticker somewhere on the bottom or back side of the device if you can't pull up a configuration page on it to tell you. Some devices can have their MAC addresses reprogrammed through their configuration pages. Be aware of that possibility if you can't find the expected MAC address connected in this list. If you can't figure out which MAC address is your print-server, disconnect it from AirPort and see that a device disappears from the list. Then reconnect it and the device that is added to the list again is the MAC address you are looking for. Write this down for the next section. If it doesn't appear in this list, then we have a real problem with the connection like possibly the print-server device's internal networking settings are messed up and need to be reset to defaults. There is some info on how to go about that at the bottom of this text.
Now, on to forcing a DHCP device connected to AirPort routers to always use a particular address:
Once you have an idea what the MAC address is of the device you want to force to use a static address, you can go about it two ways. Either you assign it an address permanently in its own configuration page (if accessible) after turning off its DHCP setting to static, or you can use its DHCP setting to set the address with the Airport Router automatically to the same address every time it reconnects to the network or is turned back on, etc. The steps with Airport need to start the same way in either case.
1. Same as before, if you haven't already, open Airport Utility, select router, click "Manual setup"
2. Click the "Internet" icon at the top. Then click the DHCP subtab.
3. To keep other devices from "Stepping on" your address that you want to assign permanently to the printer or other device, make sure the static address you choose is outside of the range of DHCP addresses setup on this page. If not, other devices could take the address away from time to time and it will cause you headaches.
Once that's set so you have an address protected from other devices getting assigned to via DHCP by limiting the DHCP address range not to include it, here's where you must choose which route to use to assign the address. You can either assign it in the printer's web-reachable configuration page (if you can figure out how to get to it and have the passwords, etc to do it, and its configuration is capable of accepting static addressing etc.. ) OR you can assign it directly from Airport's configuration (recommended). This is how to do it in Airport Utility from the DHCP controls we just opened:
1. Under the "DHCP Reservations" section, we want to click the add "+" button to set up your printer or other device for a static (but assigned) address that won't change..
2. Enter a description like "printer" or "print server" or what have you.
3. Select reservation by "MAC Address", then click "OK".
NOTE: You can use the reservation by "DHCP Client ID" to set this up as well, IF the device has a unique Client ID set in its configuration settings. I don't recommend doing so for two reasons. MAC Addresses are more hardware based, and thus, a more stable method of identification that isn't likely to change and cause you grief later. DHCP Client IDs are software-set and more subject to get wiped out if the device is reset than its MAC address as well there is the potential for two devices to be set to the same DHCP Client ID if one isn't careful, which would also cause confusion for AirPort. Most networking devices won't let you "fake" their MAC address using software settings, so MAC address can be considered the most stable and desirable method of identifying a non-computer on your network. Computers are the most likely culprits for spoofing different MAC addresses through software, so likely you don't have to worry about that with your print-server, although it's dependent on the manufacturer and what they gave it the capability to do.
4. Now here you enter the MAC address (or DHCP Client ID if so directed) of the print-server or other device you want to permanently assign the address you've chosen.
5. Lastly, enter the static IP address you want it to take on each time it is reset and requests and address again from AirPort and click done. This address will always be held available and assigned every time by Airport each time the device with the MAC address you gave it asks for a DHCP address assignment. Thus, while the device thinks its being assigned dynamic addresses, its just using the DHCP process to be assigned the same address every time by AirPort..
6. Save the changes you just made to your Airport configurations for DHCP assignments and reservations and then after Airport restarts, power-cycle your printer or other device you just setup by matching MAC address in Airport Utility and it should be assigned the new address you just specified.
7. AIRPORT TEST: Go back to the first directions in this piece to check the DHCP device connections. You should see the Mac address of the printer show up with the correctly assigned "static" IP address now in this list. If you don't, then perhaps the printer or other device assigned isn't set up for accepting an address by DHCP in its own settings. Usually this is a default behavior for any device connected to a network. If you can't open the configuration settings, at your option, you may find a pin-hole reset switch on the device you can use to reboot it with original hardware configuration settings that probably are set to DHCP.
8. Don't forget to go change your print-server settings in System Preferences of all Macs connected (and printer settings of any PCs). Your Mac needs to know the print-server's new 'permanently' assigned address in order to find it.. Be sure to save the changes..
** Be careful that you know what you are doing if you have a device that doesn't want to cooperate the way you think it should with your AirPort router. If you can't access the devices internal configuration settings in your web browser by typing its current IP address in the URL format http://.xxx.xxx.xxx.xxx, you should lookup the device manufacturer's website and search it for their support info on the device for its setup, default user-name/password and default network configuration and IP address settings to understand why you are still having trouble before you resort to resetting it by hardware reset switch. Hardware resets can sometimes have very bad results. Avoid this until the software configuration route can't be achieved by any method you try.
If you have any PCs that need to find the print-server and that setup proves to be too difficult, sometimes it helps to install Apple's Bonjour software for PCs (running Windows 2000, XP, or Vista only).... It will try to automatically locate any printers or print-servers on your network, but also makes the set-up a lot easier in general in most cases...
I hope that helps.