<p>Specific answer: use "octopi.local" rather than "octopi", since that will properly resolve to the correct Octopi IP Address.</p>

<hr>

<p>More generally, investigating the network traffic on my network (AT&amp;T Fiber Home) revealed these facts regarding the octopi server:</p>

<ul>
<li>With a browser, the octopi can be accessed via either "octopi:80" or "octopi.local:80".</li>
<li>However, "octopi" actually talks to the network router, which sends a "302" message with the target name "octopi.local".</li>
<li>So, for the browser it seems either name is correct, but in actuality only "octopi.local" is the correct network name for the octopi system.</li>
</ul>

<p>And these facts regarding the slic3r configuration:</p>

<ul>
<li>slic3r does not process "302" messages, instead treating them as errors.  This is OK, since a properly configured network won't be generating these.</li>
<li>the slic3r connection test is incomplete.  It reports success because it receives an HTTP response, even though the response is a 302 rather than the version information that it is requesting.</li>
</ul>

<p>So in this particular case, entering "octopi.local" instead of "octopi" corrected the error.  If you receive a 302 error, you will need to research and verify the exact IP address or host name for the target Octopi system.</p>

<p>A future version of slic3r should probably report an error on the "test" button if it doesn't (a) get a proper 200 return code and (b) return the proper version information as slic3r is requesting.</p>

CC BY-SA 4.0
2018-06-25T09:19:07.617Z
most software checks for 2xx series response codes as a valid ones - that it is the reason for giving the error popup :) - btw very good explanation, I will also add an option to use IP address, but that depends on internal DHCP settings
profesor79
CC BY-SA 4.0
2018-06-28T05:11:00.387Z
@profesor79, I agree. I updated the answer to clarify that the 302 error is proper behavior, and that the test function was what was confusing me.
Mark Harrison
CC BY-SA 4.0
2018-06-24T23:48:25.937Z
2018-06-28T05:09:33.430Z
2018-06-28T05:09:33.430Z
Mark Harrison
<p>I have configured slic3r's OctoPrint Upload section with the with hostname ("octopi") and port (80) of my OctoPrint server.  The Test button indicates a successful connection.</p>

<p>But when I use "Send to Printer" I get an HTTP error 302.</p>

<p>How can I fix this?
<a href="https://i.sstatic.net/PKSFV.png" rel="noreferrer"><img src="https://i.sstatic.net/PKSFV.png" alt="Error 302"></a></p>

<slic3r><octoprint>
Why does slic3r get an error "302 moved temporarily" when uploading to OctoPrint?
Mark Harrison
# Why does slic3r get an error "302 moved temporarily" when uploading to OctoPrint?

(Asked by: username_0 on 2018-06-24)

I have configured slic3r's OctoPrint Upload section with the with hostname ("octopi") and port (80) of my OctoPrint server. The Test button indicates a successful connection.

But when I use "Send to Printer" I get an HTTP error 302.

How can I fix this?
[![Error 302](https://i.sstatic.net/PKSFV.png)](https://i.sstatic.net/PKSFV.png)

**Tags:** slic3r, octoprint

---

## 1 answers

### Answer by username_0 on 2018-06-24. Score: 3 | Accepted answer

Specific answer: use "octopi.local" rather than "octopi", since that will properly resolve to the correct Octopi IP Address.

---

More generally, investigating the network traffic on my network (AT&T Fiber Home) revealed these facts regarding the octopi server:

* With a browser, the octopi can be accessed via either "octopi:80" or "octopi.local:80".
* However, "octopi" actually talks to the network router, which sends a "302" message with the target name "octopi.local".
* So, for the browser it seems either name is correct, but in actuality only "octopi.local" is the correct network name for the octopi system.

And these facts regarding the slic3r configuration:

* slic3r does not process "302" messages, instead treating them as errors. This is OK, since a properly configured network won't be generating these.
* the slic3r connection test is incomplete. It reports success because it receives an HTTP response, even though the response is a 302 rather than the version information that it is requesting.

So in this particular case, entering "octopi.local" instead of "octopi" corrected the error. If you receive a 302 error, you will need to research and verify the exact IP address or host name for the target Octopi system.

A future version of slic3r should probably report an error on the "test" button if it doesn't (a) get a proper 200 return code and (b) return the proper version information as slic3r is requesting.

> **Comments:**
> **username_1**: most software checks for 2xx series response codes as a valid ones - that it is the reason for giving the error popup :) - btw very good explanation, I will also add an option to use IP address, but that depends on internal DHCP settings  
> **username_0**: @profesor79, I agree. I updated the answer to clarify that the 302 error is proper behavior, and that the test function was what was confusing me.  

---

