Configure dwl-2100ap i have one d-link dwl 2100ap. i want configure it tow different netwok.i want two ssid .one can access only interenet and 2nd can access my network and internet.

To configure the modem properly, you should refer to the user manual. It has all the settings detailed as well as a troubleshooting list:
Link DWL 2100AP user manual

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THE ROUTER CONFIGURATION DIDN'T SAVE. ONCE YOU TURN IT OFF THE SETTING ARE LOST.
OR SOMEONE RESET IT.

I just buy another D-Link DWL-2100AP

Solution #1
Set the DWL2000AP+ as "Bridge Mode" and the new AP (DWL2100) in "WDS Mode".
On each device set the MAC address of the other device.

Solution #2
Set the DWL2100 as "WDS with AP Mode" and the DWL2000 in "Bridge Mode".
On each device set the MAC address of the other device.

The usual setup IP address for DLink wireless routers is
192.168.0.1
and the user login = admin and no password is required.
If you have not changed the password and the default SSID then it is recommended that you set a password and change the SSID so that it will help prevent someone hacking into your DLink wireles router and changing your setings to their advantage..

I have had similar problems with DWL-2100 and (much less often) with DWL-3200. I have no solution, but a workaround: changing the authentication mode. For example, if the units are using WPA-Personal, I change it (on both) to WPA2-Personal or WPA-Auto-Personal. It doesn't seem to matter which mode is used, it's just the fact of changing it that helps (eventually). You may have to go through the process more than once. Also, realize that although the web interface comes up 30 seconds or so after a reboot, it may take another 30-60 seconds before a link is established, so don't give up too soon while trying these changes.

repeater, as in a link up for wireless node to node communications?

hmmm...www.dlink.com

check your computer's warranty here FREE

I think that you trying implement NAT on this wireless access point , if you got /24 mean you can use 192.168.16.1 - 192.168.16.254 range.This kind of router do have few steps to go basically you have to provide WAN settings that your up link information, then your Broadcast information such as SSID,DHCP,WEP.WPA,etc.

drivar