I was trying openSUSE 11.0 64 bit live on my computer and to my surprise it found and was able to log into my home network without me telling it what the (not broadcasted) SSID is. The computer is connected by ethernet to the router, not wireless. I began looking for the page in Yast where this information would be entered and couldn't find it. Nor could I find any clues in the forums or with Google search. Any ideas? I don't like to think it's that easy to log into my home network and all the other distros I've tried have asked for the SSID before I can use my home network. Thanks for any help you can offer.

Aren't you using encryption? You should. Hiding the ssid can only help prevent accidental automatic connections by Windows computers. Plus for WPA-PSK, the essid provides salt for the passphrase, helping to prevent brute force attacks using rainbow tables.

Thanks for your quick response. You are right, I should be using encryption. But we have 5 computers at home and it's such a hassle to configure them all with the codes. And it slows the network down. Okay, I'm impatient. And lazy.
Anyway, to the question: even if I wanted to use encryption, where do I find the network settings in openSUSE? Thanks.

You can run "kdesu yast2 network". This will get you to YaST's gui configuration tool. Another thing you can do is edit your /etc/sysconfig/network/ifcfg-wlan0 file manually. There is a line "WIRELESS_AP=''". You can enter the MAC address of your Access Point. Doing this will keep from accessing the wrong AP but your network is wide open. Even if the ESSID isn't published, it is broadcast in the open with the packets. It only helps prevent accidental connections.

I would however recommend you use "WPA-PSK". Simply copy the key to a pen drive and use that to migrate it to all of the hosts on wireless network. If they can connect to your wireless router via it's wired switch, you can use the routers web interface and copy and paste the key as well. I use a random 64 Hex digit key. You could use something like this to generate one:
Also make sure you disable your router's wan side admin configuration (the web), wireless admin access and uPNP. Make sure you keep your router's firmware up to date. Oh, yes, I almost forgot; change your routers default username/password.

I still find my German Shepherd to be my best network defence. Anyone pulls up at my gate and wants to piggyback my wifi probably needs to whack an aerial on their car roof.
That and the mutt going nuts at the fence is a dead give-away ...

But of course I have WPA and mac address filtering turned on anyway.