<p>Use <code>stratum.bitcoin.cz</code> and port <code>3333</code> in GUIMiner, <strong>not</strong> like <a href="http://stratum.bitcoin.cz:3333" rel="nofollow">http://stratum.bitcoin.cz:3333</a> that was mensioned in another answer.</p>

CC BY-SA 3.0
2013-06-16T13:21:46.073Z
2014-05-29T15:01:22.723Z
2014-05-29T15:01:22.723Z
stef
<p>The problem is that in GUIMiner, the URL for <strong>Slush's pool</strong> is:</p>

<blockquote>
  <p>api2.bitcoin.cz:8332</p>
</blockquote>

<p>That address has been deprecated, and it falls back to the <em>GetWork</em> protocol. From <a href="http://mining.bitcoin.cz/" rel="nofollow">Slush's Pool news</a>:</p>

<blockquote>
  <p>10.03.2013<br>
  Default mining URL for <em>Stratum</em> is <code>stratum.bitcoin.cz:3333</code>. If you're still using <code>api.bitcoin.cz</code>, please fix your URL to prevent fallback to deprecated <em>Getwork</em> protocol.</p>
</blockquote>

<p>In the GUIMiner interface, instead of choosing "Slush's Pool" from the dropdown menu, choose "other" and then enter</p>

<p><strong><a href="http://api.bitcoin.cz:8332" rel="nofollow">http://api.bitcoin.cz:8332</a></strong></p>

<p>or</p>

<p><strong>stratum.bitcoin.cz:3333</strong></p>

CC BY-SA 3.0
2013-05-26T21:37:38.977Z
Nice, it worked!
j4nSolo
CC BY-SA 3.0
2014-01-05T18:11:55.083Z
When I tried it with the CPU miner (*not GPU*), *api.bitcoin.cz:8332* worked, but *stratum.bitcoin.cz:3333* did **not** work.
Peter Mortensen
CC BY-SA 3.0
2013-05-26T18:13:06.193Z
2014-05-29T21:21:02.400Z
2014-05-29T21:21:02.400Z
zoigo
<p>I started co-mining on <a href="https://mining.bitcoin.cz/stats/" rel="nofollow">Slush's pool</a> successfully for about 48 hours, but from there on I haven't been able to connect to it again. It logs in the console this, no matter if I'm using a valid worker and password or not:</p>

<pre><code>2013-05-26 12:55:19: Listener for "Default" started
2013-05-26 12:55:20: Listener for "Default": api2.bitcoin.cz:8332 26/05/2013 12:55:20, checking for stratum...
2013-05-26 12:55:20: Listener for "Default": api2.bitcoin.cz:8332 26/05/2013 12:55:20, started OpenCL miner on platform 0, device 0 (Turks)
2013-05-26 12:55:20: Listener for "Default": api2.bitcoin.cz:8332 26/05/2013 12:55:20, no response to getwork, using as stratum
2013-05-26 12:55:20: Listener for "Default": api2.bitcoin.cz:8332 26/05/2013 12:55:20,  No JSON object could be decoded
2013-05-26 12:55:30: Listener for "Default": api2.bitcoin.cz:8332 26/05/2013 12:55:30, Failed to subscribe
2013-05-26 12:55:32: Listener for "Default": api2.bitcoin.cz:8332 26/05/2013 12:55:32, IO errors - 1, tolerance 2
2013-05-26 12:55:33: Listener for "Default" shutting down
</code></pre>

<p>Of course, I've checked my connection, and I've started <a href="http://guiminer.org/" rel="nofollow">GUIMiner</a> with administrator privileges. I'm using Windows&nbsp;7.</p>

<mining-pools><mining-software><connection>
GUIMiner won't start mining on Slush's pool
j4nSolo
# GUIMiner won't start mining on Slush's pool

(Asked by: username_0 on 2013-05-26)

I started co-mining on [Slush's pool](https://mining.bitcoin.cz/stats/) successfully for about 48 hours, but from there on I haven't been able to connect to it again. It logs in the console this, no matter if I'm using a valid worker and password or not:

```
2013-05-26 12:55:19: Listener for "Default" started
2013-05-26 12:55:20: Listener for "Default": api2.bitcoin.cz:8332 26/05/2013 12:55:20, checking for stratum...
2013-05-26 12:55:20: Listener for "Default": api2.bitcoin.cz:8332 26/05/2013 12:55:20, started OpenCL miner on platform 0, device 0 (Turks)
2013-05-26 12:55:20: Listener for "Default": api2.bitcoin.cz:8332 26/05/2013 12:55:20, no response to getwork, using as stratum
2013-05-26 12:55:20: Listener for "Default": api2.bitcoin.cz:8332 26/05/2013 12:55:20,  No JSON object could be decoded
2013-05-26 12:55:30: Listener for "Default": api2.bitcoin.cz:8332 26/05/2013 12:55:30, Failed to subscribe
2013-05-26 12:55:32: Listener for "Default": api2.bitcoin.cz:8332 26/05/2013 12:55:32, IO errors - 1, tolerance 2
2013-05-26 12:55:33: Listener for "Default" shutting down

```

Of course, I've checked my connection, and I've started [GUIMiner](http://guiminer.org/) with administrator privileges. I'm using Windows 7.

**Tags:** mining-pools, mining-software, connection


---

## 2 answers

### Answer by username_2 on 2013-05-26. Score: 12 | Accepted answer

The problem is that in GUIMiner, the URL for **Slush's pool** is:

> api2.bitcoin.cz:8332

That address has been deprecated, and it falls back to the *GetWork* protocol. From [Slush's Pool news](http://mining.bitcoin.cz/):

> 10.03.2013  
> Default mining URL for *Stratum* is `stratum.bitcoin.cz:3333`. If you're still using `api.bitcoin.cz`, please fix your URL to prevent fallback to deprecated *Getwork* protocol.

In the GUIMiner interface, instead of choosing "Slush's Pool" from the dropdown menu, choose "other" and then enter

**<http://api.bitcoin.cz:8332>**

or

**stratum.bitcoin.cz:3333**

> **Comments:**
> **username_0**: Nice, it worked!  
> **username_3**: When I tried it with the CPU miner (*not GPU*), *api.bitcoin.cz:8332* worked, but *stratum.bitcoin.cz:3333* did **not** work.  

---

### Answer by username_1 on 2013-06-16. Score: 1

Use `stratum.bitcoin.cz` and port `3333` in GUIMiner, **not** like <http://stratum.bitcoin.cz:3333> that was mensioned in another answer.


---

