Got it, let's walk through exactly how to set up permanent, dynamic redirects from your old ASP URLs to the new PHP ones—while keeping your Google rankings intact. This is all about using 301 permanent redirects (the only redirect type that preserves SEO value) and matching those dynamic id parameters correctly. Here are your options based on your current setup:

Option 1: Use IIS URL Rewrite (If Old Windows Host Is Still Accessible) #

If your legacy ASP site is still running on Windows IIS, the cleanest approach is to use IIS's URL Rewrite module. No need to modify your ASP code—just add rules to your web.config:

1. First, make sure the IIS URL Rewrite module is installed (check in IIS Manager > Modules; if missing, install it via the IIS Administration Pack).
2. Add this rule to your site's web.config file:

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
  <system.webServer>
    <rewrite>
      <rules>
        <rule name="ASP News to PHP Redirect" stopProcessing="true">
          <!-- Match the old ASP path exactly -->
          <match url="^news/article\.asp$" />
          <!-- Capture the dynamic id parameter from the query string -->
          <conditions>
            <add input="{QUERY_STRING}" pattern="id=(\d+)" />
          </conditions>
          <!-- Redirect to the new PHP URL, passing the captured id -->
          <action type="Redirect" url="https://www.example.com/article.php?cat=1&amp;id={C:1}" redirectType="Permanent" />
        </rule>
      </rules>
    </rewrite>
  </system.webServer>
</configuration>

• {C:1} pulls the numeric id value from the old URL and inserts it into the new one.
• redirectType="Permanent" sends a 301 status code, which tells search engines the page has moved forever.

Option 2: Modify the Legacy ASP Page (If Rewrite Module Isn't Available) #

If you can't use IIS Rewrite, you can add redirect logic directly to your article.asp file. Put this code at the very top of the page (before any other content):

<%@ Language=VBScript %>
<%
' Grab the id parameter from the old URL
Dim articleId
articleId = Request.QueryString("id")

' Validate the id is a number to avoid bad requests
If IsNumeric(articleId) Then
    ' Send a 301 permanent redirect header
    Response.Status = "301 Moved Permanently"
    Response.AddHeader "Location", "https://www.example.com/article.php?cat=1&id=" & articleId
    ' Stop execution so the old ASP content doesn't load
    Response.End()
End If

' Fallback: Redirect invalid requests to your news list page
Response.Redirect "https://www.example.com/news.php", False
%>

This checks for a valid numeric id, sends the 301 redirect, and stops the rest of the ASP page from running.

Option 3: Configure Redirects on Your New Linux Host (If Domain Is Already Pointed There) #

If you've already moved your domain to the Linux host running the PHP site, set up redirects in Apache or Nginx:

Apache (Using .htaccess) #

Add these lines to your site's root .htaccess file:

RewriteEngine On

# Match old ASP URL and capture the id parameter
RewriteCond %{QUERY_STRING} ^id=(\d+)$
RewriteRule ^news/article\.asp$ https://www.example.com/article.php?cat=1&id=%1 [R=301,L]

• %1 refers to the captured id value from the query string.
• R=301 triggers a permanent redirect, L tells Apache to stop processing further rules.

Nginx #

Add this to your server block configuration:

# Redirect ASP news URLs to PHP, passing the id parameter
rewrite ^/news/article\.asp$ https://www.example.com/article.php?cat=1&id=$arg_id permanent;

For stricter validation (only match numeric ids), use:

if ($query_string ~ "^id=(\d+)$") {
    rewrite ^/news/article\.asp$ https://www.example.com/article.php?cat=1&id=$1 permanent;
}

$arg_id automatically pulls the id parameter from the request, and permanent sends a 301 status code.

Critical SEO Steps to Avoid Losing Rankings #

• Stick to 301 redirects: Never use 302 (temporary) redirects—they don't pass SEO authority from the old page to the new one.
• Match content closely: Ensure your new PHP page has the same (or better) content as the old ASP page. Google won't transfer rankings if the content is drastically different.
• Update Google Search Console: Go to Settings > Change of address to tell Google you've moved your site's URL structure. This speeds up index updates.
• Submit a new sitemap: Generate a sitemap for your new PHP site and submit it to Google Search Console. Keep the old sitemap active for a few months to catch any lingering old URLs.
• Check external links: If you know of external sites linking to your old ASP URLs, reach out to ask them to update links. 301s will handle these automatically, but updating links directly is better long-term.

内容的提问来源于stack exchange，提问作者Anush M