这是以前用ASP写的，本想改成ASP.net的给大家，后来想大家能看懂算法就行了。IP比对的关键是IP地址的线性化，下面就是代码。
'可以进入的ip '218.7.44.0 - 218.7.45.253 '61.180.240.0 - 61.180.240.253 '202.118.208.0 - 202.118.223.253 ' '218.7.44.0 3657903103 '218.7.45.253 3657903612 ' '61.180.240.0 1035268095 '61.180.240.253 1035268348 ' '202.118.208.0 3396784127 '202.118.223.253 3396788220 ip=request.servervariables("remote_addr") sip=split(ip,".") num=cint(sip(0))*256*256*256+cint(sip(1))*256*256+
cint(sip(2))*256+cint(sip(3))-1 response.write(ip) response.write("<br>") if ((num>=3657903103 and num<=3657903612) or
(num>=1035268095 and num<=1035268348) or (num>=3396784127 and num<=3396788220)) then response.write("抱歉，您的ip不合法！") response.End() else response.write("您的ip合法") end if