I am one of these older web developers still insisting on hosting on my own server and therefore also managing IIS myself. This Topiq is a documentation of the most common IIS redirects I need to do.

Index :

• Redirect http -> https
• Redirect subdomain -> domain
• Redirect old-domain -> new-domain

Appendixes :

• Understanding IIS Redirection Rules

Note that in this tutorial I use the IIS Redirect UI to create the redirect rules, however the Redirect UI will save the redirect rules to web.config and then IIS is serving a website, it will apply the redirect rules as found in web.config - you can therefore also just write (or copy) any redirect rule directly into the web.config.

Redirect http to https

Steps to setup http to https redirection in IIS:

1. Open IIS and select the website for which you want to redirect http -> https and then double click on the "URL Rewrite" icon.
2. Click the "Add Rule(s).." link in the right pane.
3. Under "Inbound rules" select the "Blank rule" option and click the "OK" button.
4. On the "Edit Inbound Rule" page :
   1. Name: http to https
   2. Match URL
      1. Requested URL: Matches the Pattern
      2. Using: Regular Expressions
      3. Pattern: (.*) : capture the full path.
      4. Ignore case: true
   3. Conditions
      1. Logical grouping: Match All
      2. Add condition
         1. Click the "Add" button.
         2. Fill in the "Add Condition" dialog
            1. Condition input: {HTTPS} : returns either ON or OFF whether the request came through a secure channel.
            2. Check if input string: Matches the Pattern
            3. Pattern: ^OFF$ : only activate this rule if the request come through an unsecure channel.
            4. Ignore case: true
         3. Press the "OK" button to save the condition.
         4. Redirect match condition is added.
      3. Track capture groups across conditions: false
   4. Server Variables : No server variables will be used.
   5. Action
      1. Action Type: Redirect
      2. Action Properties
         1. Redirect URL: https://{HTTP_HOST}/{R:0} : redirect to the requested domain {HTTP_HOST} appending the requested path {R:0} captured in the Match URL Pattern.
         2. Append query string: true
         3. Redirect type: Permanent (301)
   6. Press the "Apply" button in the right Actions pane.
5. http to https redirect rule successfully created.

How the http to https redirect rule is looking in web.config:

<configuration>
    <system.webServer>
       <rewrite>
           <rules>
               <rule name="http to https" stopProcessing="true">
                   <match url="(.*)" />
                   <conditions>
                       <add input="{HTTPS}" pattern="^OFF$" />
                   </conditions>
                   <action type="Redirect" url="https://{HTTP_HOST}/{R:0}" />
               </rule>
           </rules>
       </rewrite>
   </system.webServer>
</configuration>

Note that alternatively to the http to https redirection rule, you can in ASP.NET Core also setup redirection VERY EASILY using the redirection middleware in the request pipeline like this :

public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
   app.UseHttpsRedirection();
   //... other pipeline configuration
}

Also note that UseHttpsRedirection() in ASP.NET Core is unnessary if served behind a reverse proxy (here IIS) already implementing http to https.

Redirect subdomain to main domain

Here from www.topiqs.online to topiqs.online.

Steps to redirect subdomain to main domain:

1. Open IIS and select the website for which you want to redirect http -> https and then double click on the "URL Rewrite" icon.
2. Click the "Add Rule(s).." link in the right pane.
3. Under "Inbound rules" select the "Blank rule" option and click the "OK" button.
4. On the "Edit Inbound Rule" page :
   1. Name: subdomain to main domain
   2. Match URL
      1. Requested URL: Matches the Pattern
      2. Using: Regular Expressions
      3. Pattern: (.*) : capture the full path.
      4. Ignore case: true
   3. Conditions
      1. Logical grouping: Match All
      2. Add condition
         1. Click the "Add" button.
         2. Fill in the "Add Condition" dialog
            1. Condition input: {HTTP_HOST} : get the requested domain to test the pattern against.
            2. Check if input string: Matches the Pattern
            3. Pattern: www.topiqs.online : only activate the redirect rule if the requested domain is www.topiqs.online.
               (Note that if you have more than one subdomain binding that you want to redirect, you can use a more general pattern like eg. .+\.topiqs.online - here catching ALL subdomains)
            4. Ignore case: true
         3. Press the "OK" button to save the condition.
         4. Redirect match condition is added.
      3. Track capture groups across conditions: false
   4. Server Variables : No server variables will be used.
   5. Action
      1. Action Type: Redirect
      2. Action Properties
         1. Redirect URL: https://topiqs.com/{R:0} : redirect to top domain and append the request Path.
         2. Append query string: true
         3. Redirect type: Permanent (301)
   6. Press the "Apply" button in the right Actions pane.
5. http to https redirect rule successfully created.

How the IIS subdomain redirect rule looks in web.config :

<configuration>
   <system.webServer>
       <rewrite>
           <rules>
               <rule name="subdomain to main domain" stopProcessing="true">
                   <match url="(.*)" />
                   <conditions>
                       <add input="{HTTP_HOST}" pattern="www.topiqs.online" />
                   </conditions>
                   <action type="Redirect" url="https://topiqs.online/{R:0}" />
               </rule>
           </rules>
       </rewrite>
   </system.webServer>
</configuration>

Redirect old-domain to new-domain

I had this problem when I wanted to change a domain name from manylink.online to topiqs.online. Redirecting the domain ensures that :

• Users finding content via Google on the manylink.online domain will be redirected to the same content on topiqs.online.:
• I think (and am nearly sure) that canonical urls are unnecessary on existing content on old-domain (manylink.online).

There are 2 methods to create the old-domain to new-domain redirection:

• Add a URL Redirect rule in IIS : the method I now use.
• Add a URL Redirect DNS record : easiest method but problematic.

Steps to redirect old-domain to new-domain in IIS:

1. Open IIS and select the old-domain website for which you want to redirect from and then double click on the "URL Rewrite" icon.
2. Click the "Add Rule(s).." link in the right pane.
3. Under "Inbound rules" select the "Blank rule" option and click the "OK" button.
4. On the "Edit Inbound Rule" page :
   1. Name: redirect to topiqs.online
   2. Match URL
      1. Requested URL: Matches the Pattern
      2. Using: Regular Expressions
      3. Pattern: (.*) : capture the full path.
      4. Ignore case: true
   3. Conditions
      1. Logical grouping: Match All
      2. Add condition
         1. Click the "Add" button.
         2. Fill in the "Add Condition" dialog
            1. Condition input: {HTTP_HOST} : get the requested domain to test the pattern against.
            2. Check if input string: Matches the Pattern
            3. Pattern: manylink.online : only activate the rule if the domain contains "manylink.online".
            4. Ignore case: true
         3. Press the "OK" button to save the condition.
         4. Redirect match condition is added.
      3. Track capture groups across conditions: false
   4. Server Variables : no server variables will be used.
   5. Action
      1. Action type: Redirect
      2. Action Properties
         1. Redirect URL: https://topiqs.online/{R:0} : redirect to topiqs.online and append the request Path.
         2. Append query string: true
         3. Redirect type: Permanent (301)
   6. Press the "Apply" button in the right Actions pane.
5. old-domain to new-domain redirect rule successfully created.

How the IIS domain redirect rule looks in web.config :

<configuration>
   <system.webServer>
       <rewrite>
           <rules>
               <rule name="redirect to topiqs.online" stopProcessing="true">
                   <match url="(.*)" />
                   <conditions>
                       <add input="{HTTP_HOST}" pattern="manylink.online" />
                   </conditions>
                   <action type="Redirect" url="https://topiqs.online/{R:0}" />
               </rule>
           </rules>
       </rewrite>
   </system.webServer>
</configuration>

URL Redirect DNS records

If you have edit access to your domains DNS records, redirect an old domain to a new domain is most easily done by a URL Redirect DNS record.

There are 3 types of URL Redirect DNS records:

• 301 Unmasked Permanent Redirect : new-domain is shown in browsers url field and new-domain is indexed by search engines.
• 302 Unmasked Redirect : new-domain is shown in browsers url field but old-domain is indexed by search engines.
• Masked Redirect : old-domain is shown in browsers url field. I don't know exactly how search engines is handling this, my guess is it is not good.

However, there are 2 reasons I do NOT any longer use URL Redirect DNS records :

• Most importantly I had the problem that a DNS Redirect DNS record messed up browsers connection process sometimes taking more than 20 seconds to just connect - it tooks me so loooong time to figure it out that I am too ashamed of talking about it in public.
• Another problem I experienced then applying a URL Redirect DNS records was that requesting a LetsEncrypt certificate fails with the following error "Authorization result: invalid" & "Timeout during connect (likely firewall problem)" (see How to install LetsEncrypt SSL/TLS certificate on IIS for more info on that error).

Appendix : Understanding IIS Redirection Rules

The main flow of an IIS Redirect rule typically consist of these 3 main steps :

1. Match the request path for situations where we want to redirect and also capture parts of the url for back references - denoted R:X, eg. the full match is R:0.
2. Setup further conditions for whether we want to redirect and also capture parts of the conditions for back references - denoted C:X, eg. the full match is C:0.
3. Create the redirect rule possibly using any back references R:X & C:X.

Then using the IIS Rewrite/Redirection UI to build the redirect rule (rather than writing to the web.config directly), there are 3 fields matching the above 3 main steps :

• Match URL > Pattern : regards the request Path (not the protocol, not the domain, not the query string). In the Redirect URL field (below) we can refer to the whole path as {R:0} and if we use capture groups, eg. /home/(category), we can refer to them using the group number, eg. here {R:1} would be "category". In all the examples above I just use (.*), which means that {R:0} & {R:1} hold the same value.
• Conditions :
  • Condition input : the input seems to be in terms of server variables.
    • {QUERY_STRING} : returns the request querystring.
    • {HTTP_HOST} : I am unsure what this variable returns precisely, however assuming it returns the request hostname have so far worked for me.
    • {HTTPS} : returns ON if the request came through a secure channel (eg. SSL), otherwise it returns OFF.
• Action > Action Properties > Redirect URL : if the redirect rule is activated (based on the Match URL > Pattern and any Conditions), then send send the Redirect URL back to the browser (together with the redirect http code).