Question

On my website, I have a situation where my URL sometimes get a querystring parameter appended by a system outsite ours.

So instead of looking like this: http://www.domain.com?myquery=blah or http://www.domain.com, it has the url http: http://www.domain.com?myquery=blah&theirpara=blah or http://www.domain.com?theirpara=blah .

When a user visits with the “theirpara” parameter, I would like to make a 301 redirect to the URL without it.

I’ve tried using the URL rewrite module, but not really getting anywhere. It would be nice to do it at IIS/web.config level instead of Response.RedirectPermanent if possible.

I thought it would be good to setup up using a rule (URL write module), but to be honest, I’ve no idea how to fix this issue. I am using the following rule to remove the trailing slash, but not sure how to modify it to this need.

<!--To always remove trailing slash from the URL-->
<rule name="Remove trailing slash" stopProcessing="true">
  <match url="(.*)/$" />
  <conditions>
    <add input="{REQUEST_FILENAME}" matchType="IsFile" negate="true" />
    <add input="{REQUEST_FILENAME}" matchType="IsDirectory" negate="true" />
  </conditions>
  <action type="Redirect" redirectType="Permanent" url="{R:1}" />
</rule>

Any ideas on how to set it up?

Answer 1

I don’t have an IIS to hand but the following should be working:

Change match to

<match url="(.*)&theirpara=blah(.*)" />

and redirect to

<action type="Redirect" redirectType="Permanent" url="{R:1}{R:2}" />

If you want it to work not only on the plain domain you should remove the conditions accordingly.