I'm having some trouble creating a urlacl reservation in Windows Server 2008; probably this a rookie mistake.

The command line I'm using is:

netsh http add urlacl url=http://+:99898/ user=ben

The error that I see is:

Url reservation add failed, Error: 87
The parameter is incorrect.

There is a local user account named 'ben' that has admin privileges. I've made sure to put a trailing slash after the port number in the URL. Google and MSDN documentation are letting me down now - does anyone have any clue what I'm doing incorrectly?

  • Did this question make anybody think of TV crime shows with "IP addresses" like "10.68.342.12" in them? >smile< Jun 23, 2011 at 3:40
  • I'll take my lumps here... =)
    – Ben
    Jun 23, 2011 at 4:44
  • Also, as usual, if you have a user name that includes a space, use double-quotes to encapsulate it. e.g., C:\>netsh http add urlacl url=http://+:9998/ user="DOMAIN\my name"
    – lewiSnort
    Nov 14, 2018 at 1:29

3 Answers 3


Port number "99898" isn't a valid TCP port number. TCP port numbers are 16-bit unsigned integers, so they can't exceed 65535. I would strongly suspect that this invalid port number is the reason for the error you're seeing.

  • That's it - I tried with a 4-digit port number earlier, but must have gotten a different error. Thanks!
    – Ben
    Jun 23, 2011 at 0:21

I had the same error; in my case, the mistake I was making was omitting the trailing slash from the URL:

C:\>netsh http add urlacl url=http://+:8085 user=DOMAIN\myname
Url reservation add failed, Error: 87
The parameter is incorrect.

C:\>netsh http add urlacl url=http://+:8085/ user=DOMAIN\myname
URL reservation successfully added
  • And in my case, I had omitted the url= and user=, which the documentation says are optional, but are apparently not.
    – Cameron
    Jun 2, 2016 at 15:32
netsh http add urlacl url=https://*:8081/ user=Everyone

Also the trailing slash does matter -------------^

  • 1
    Could you improve the quality of your answer by pointing out why your answer is the solution?
    – John K. N.
    Oct 28, 2016 at 11:36

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