Use the servervariables attribute of the request object to obtain the value of the environment variable. The syntax used is: request. servervariables (variable), "variable" indicates the name of the environment variable, such as the server host name and web server software name. If "variable" is "remote_addr", it indicates the visitor's IP address, it can be used to filter IP addresses.
SourceProgram(File Name: Demo. asp)
<HTML>
<Head>
<Meta http-equiv = "Content-Type" content = "text/html; charset = gb_2312-80">
<Meta name = "generator" content = "Microsoft FrontPage express 2.0">
<Style>
<! --
. As {Line-Height: 15px; font-size: 9pt}
A: hover {color: RGB (0,51, 240); text-Decoration: underline}
. P9 {font-family: ""; font-size: 9pt; line-Height: 15pt}
. P12 {font-family: ""; font-size: 12pt; line-Height: 18pt}
A: link {text-Decoration: none ;}
A: visited {text-Decoration: none ;}
A: hover {text-Decoration: underline; font-size: 125%; color: Blue}
-->
</Style>
<Title> ASP page firewall function demonstration </title>
</Head>
<Body background##back.jpg ">
<%
'Use request. servervariables ("remote_addr") to obtain the IP address and save it in the rip variable.
Rip = request. servervariables ("remote_addr ")
Strip = CSTR (RIP)
'Obtain the value of the third segment of the IP address and save it to strip.
For I = 1 to 2
Strip = right (strip, Len (strip)-instr (1, strip, ".")
Next
Strip = left (strip, instr (1, strip, ".")-1)
'The IP address validity test and password verification, including two aspects:
'Verification is performed if the IP address meets the requirements. If the IP address does not match the requirements, check whether the entered password is correct (the password here is "asp ")
If (left (RIP, 5) <> "127.1" or strip <"1" or strip> "50") and request ("passwd") <> "asp" then
%>
<P> <font color = "# ff0000"> sorry, your IP address is <% = rip %>. The IP address that can be accessed on this page is 127.1.1. * To 127.1.50. * If you are a user on the Intranet, make sure your browser does not use a proxy! <Br> </font> </P>
<Form action = "demo. asp" method = "Post" id = form1 name = form1>
<P> enter the access password: <input type = "password" name = "passwd"> <input type = "Submit" value = "OK" name = "B1">;
</P>
</Form>
<% Else %>
'The pages accessible to legal users can add any information here
Congratulations! You have successfully passed the page security certification and can directly use the resources on this site!
<% End if %>
</Body>
</Html>
In actual use, you only need to slightly modify the above program (such as the IP address and other information), of course, this is only implemented in a page security protection function, if a website has multiple pages, you can set a session variable to flag the user for judgment on the following page.