Okay, let's step back and try again from the beginning.
You have a small network with a router (the TC), a computer (the Mac), another computer (a WinBox), and another device (the printer), correct?
If so, then you should do the following:
1 Launch AirPort Utility. The current version is 5.5.2. You should ensure that your TC has the latest firmware, which I believe is 7.5.2. You can get the latest version of the APU and the latest firmware from Apples' download site, at <http://support.apple.com/kb/DL1106>.
2 Once you have the latest APU and firmware, restart the APU and select the 'manual' button. This should take you to the main page for the APU. You should be in the 'Airport' main tab. There should be four sub-tabs: Summary, Base Station, Wireless, and Access Control. You should be on Summary. Summary should list the following:
the name of the TC;
its operational status (if running properly, there should be a green dot. if not, there should be a yellow or a red dot, depending on the severity of the problems. If there are problems, then the number of problems will be displayed here.);
the firmware version number (this should be 7.5.2);
its serial number;
the wireless MAC address;
the wired MAC address;
the wireless operation mode (create a network, extend a network, join another network);
the security level (avoid 'open' and 'WEP' if at all possible);
the wireless channel (in the US, that's usually 6 or 11);
the number of clients currently connected by wireless;
how the TC is connected to the rest of the Internet;
and what the Internet IP address is.
2 Select 'Base Station'. This will allow you to change/update the TC's name and password, to reset the system time and set the time zone, and to allow certain settings. Turn
OFF 'Allow setup over WAN', that is a security hole.
3 Select 'Wireless'. This will allow you to change/update the TC's broadcast wireless ID, set the wireless mode, and change the wireless access encryption (open/WEP/WPA/WPA2) and passphrase. Choose WPA or WPA2. Use a good passphrase, at least 8 digits, 10 or 12 is better, at least one capital letter, at least one number, at least one non-alphanumeric symbol, and at least on common letter. In your case you want the wireless mode to be set for 'create a wireless network'
4 Select 'Access Control'. Set MAC access control to 'not enabled'.
5 you should now select the 'Internet' main tab. There are again four sub-tabs: Internet Connection, TCP/IP, DHCP, and NAT. You should be on Internet Connection. If you are connected using a cable modem, select 'Ethernet'. If you are connected using a DSL modem, use PPPoE and enter your telephone company-supplied username and password. Leave everything else alone.
6 Select TCP/IP. This should be the settings for the external connection, the connection to your ISP. If all is set correctly you will be seeing data pre-populated here. Don't change it.
7 Select DHCP. This should be the settings for the
internal connection, for your local network. Here is where you find out what your network is set for. Apple sets up a Class A private network (for reasons best known in Cupertino; a Class A can have up to 16,777,214 clients, and a TC or AE would melt under that kind of load.) I usually set my systems up to have a Class C private network, which can have a maximum of 254 clients. Class C networks start with 192.168. That's one of the choices in the system. I'd pick the Class C, for simplicity's sake. The DHCP beginning address, by default, is .1.2; I usually make that .1.100. The DHCP ending address, by default, is .1.200, you can leave that alone. This gives you a DHCP pool of 101 address, from 100 to 200, inclusive. A DHCP pool that size is vast overkill for your network, but it'll work. And it's way smaller than the DHCP pool for a Class A. You can also set up DHCP reservations for certain devices, which will force the TC to give a particular IP address to a particular device. More on this later.
8 select NAT. If anything inside here is selected, deselect it.
9 the 'Printers' and 'Disks' tabs are for attaching devices by USB to the TC or AE. Leave them alone.
10 it's a bad idea to play with the 'Advanced' tab unless you know what you're doing.
11 You have now configured the TC. You need to fire up your computers and the printer. The first thing you do is to set them all to use DHCP to connect to your TC. The TC will now hand them out an IP, and so long as they can see the TC they will connect. _If they can't see the TC they will not connect_. Note that if you have a fixed IP for those devices, which is what you seem to have had before, then you can have two problems:
a) if the TC has DHCP turned on, which it seems to, and if your fixed IPs are in the DHCP pool, which it seems they are, then the TC will occasionally hand out an IP which is identical to that of one or more of your fixed IPs. You will then have an IP conflict; you can't have two devices with the same IP on the same network. This is one of the causes of your problem. Putting everyone on DHCP will solve that; the TC will ensure that each device gets an IP of its own and will maintain a list of who got which IP. These IPs are 'leased'; the default is for one day, but you can change it in the DHCP sub-tab to whatever you like. (I usually use 8 days.) At the end of the lease, the TC will check to see if the device is still connected, and if it is, will renew the lease. If it isn't, it will drop the lease. If the device reconnects and the old IP is still available the TC will usually hand it back. If something else has grabbed the IP in the meantime, the TC will give the device a new IP.
b) the fact that you have an IP when you have a fixed IP does not mean that you have connectivity. Your devices simply may not be able to see the TC. If you turn on DHCP and use that, then you will
know if your device can see the TC or not. If it can, it will get an IP in the standard range. If it can't, it will get an APIPA address, an Automatic Private IP Address, in the 169.254 range... and you will
know that there's a problem. Right now you can't know.
The normal way to hand out a fixed IP is to use an IP from
outside of the DHCP pool. Your IPs are all inside the pool. If you were to change them to IPs larger than 200 (but smaller than 254) then you might avoid problems. (10.0.1.201, for example...) However, if you want to be sure which IP your devices get but don't want to use fixed IPs, there's another way: reserved IPs. You find the MAC addresses for your devices (the Ethernet and Airport addresses in System Preferences/Network for Macs, the hardware addresses for the WinBox and the printer) and you enter them into the reserved box in the DHCP sub-tab, one MAC address per line, and the TC will assign one IP from the DHCP pool to each MAC address. The lease will never expire and that device will always get that IP.
Message was edited by: Charles Dyer
