<p>The testnet networks are very similar to each other. I listed all of the <a href="https://bitcoin.stackexchange.com/questions/9975/has-the-testnet-ever-been-reset">testnet resets</a> here, and it seems like they make the minimum changes necessary to create a new blockchain.</p>

<p>It seems like the testnet3 reset came about because of compatibility issues:</p>

<blockquote>
  <p>"Mark III" because this is the third genesis block for the testnet. The
  main reason for the reset is to get a more 'sane' test network; with the
  BIP16 and BIP30 and testnet difficulty blockchain rule changes the old
  testnet is a mess, with old clients serving up different, incompatible
  chains.</p>
</blockquote>

<p>(<a href="http://sourceforge.net/p/bitcoin/mailman/message/29331507/" rel="nofollow noreferrer">Source.</a>)</p>

<p>The creation of testnet2 predates the Bitcoin mailing list, but given this discussion in #bitcoin-dev, I think it happened because difficulty on testnet was too high:</p>

<pre><code>17:04   slush   btw any chance to reset testnet?
17:05   tcatm   you could use your pool and a modified bitcoind to reset it in about 6 hours
17:05   slush   no, I don't want to connect pool to testnet ;)
17:06   slush   But new genesis block in next release should solve this, right?
17:07   gavinandresen   You talking about possible testnet reset?
17:08   slush   it would be nice. It's practically impossible to 'test' anything on testnet :)
17:08   gavinandresen   If you have two machines you can create your own private testnet
17:09   gavinandresen   ... but you can't test until they've generated at least 100 blocks.
17:10   slush   gavinandresen: agree, but is there any reason for keeping difficulty so high?
17:10   gavinandresen   Nope
[Edited for length.]
</code></pre>

<p>(<a href="http://bitcoinstats.com/irc/bitcoin-dev/logs/2011/01/30#l1296407063" rel="nofollow noreferrer">Source.</a>)</p>

CC BY-SA 3.0
2015-03-24T19:46:36.070Z
2015-03-28T06:23:18.277Z
2017-04-13T12:47:33.660Z
Nick ODell
<p>From <a href="https://en.bitcoin.it/wiki/Testnet" rel="nofollow">Bitcoin Wiki: Testnet</a></p>

<blockquote>
  <p>There have been three generations of testnet. Testnet2 was just the first testnet reset with a different genesis block, because people were starting to trade testnet coins for real money. Testnet3 is the current test network. It was introduced with the 0.7 release, introduced a third genesis block, a new rule to avoid the "difficulty was too high, is now too low, and transactions take too long to verify" problem, and contains blocks with edge-case transactions designed to test implementation compatibility.</p>
</blockquote>

<p>I'm interested to know about Testnet(1) and Testnet2: the differences, the reason each version was deprecated (in particular, how/why people were selling TBTCs). I'm interested in the "historical context" as much as I am technical reasons for changing to a new Testnet version.</p>

CC BY-SA 3.0
2015-02-28T05:37:25.640Z
I think this is a duplicate of [Has the testnet ever been reset?](http://bitcoin.stackexchange.com/questions/9975/has-the-testnet-ever-been-reset), but I'm not sure.
Nick ODell
CC BY-SA 3.0
2015-02-28T07:42:23.333Z
I suppose it is quite similar; I'll rephrase because what I was curious about was the circumstances of resetting; or is it just simply that resetting stops hoarding?
Wizard Of Ozzie
<testnet><history>
Testnet version history
Wizard Of Ozzie
# Testnet version history

(Asked by: username_0 on 2015-02-28)

From [Bitcoin Wiki: Testnet](https://en.bitcoin.it/wiki/Testnet)

> There have been three generations of testnet. Testnet2 was just the first testnet reset with a different genesis block, because people were starting to trade testnet coins for real money. Testnet3 is the current test network. It was introduced with the 0.7 release, introduced a third genesis block, a new rule to avoid the "difficulty was too high, is now too low, and transactions take too long to verify" problem, and contains blocks with edge-case transactions designed to test implementation compatibility.

I'm interested to know about Testnet(1) and Testnet2: the differences, the reason each version was deprecated (in particular, how/why people were selling TBTCs). I'm interested in the "historical context" as much as I am technical reasons for changing to a new Testnet version.

**Tags:** testnet, history

> **Comments:**
> **username_1**: I think this is a duplicate of [Has the testnet ever been reset?](http://bitcoin.stackexchange.com/questions/9975/has-the-testnet-ever-been-reset), but I'm not sure.  
> **username_0**: I suppose it is quite similar; I'll rephrase because what I was curious about was the circumstances of resetting; or is it just simply that resetting stops hoarding?  

---

## 1 answers

### Answer by username_1 on 2015-03-24. Score: 2 | Accepted answer

The testnet networks are very similar to each other. I listed all of the testnet resets here, and it seems like they make the minimum changes necessary to create a new blockchain.
It seems like the testnet3 reset came about because of compatibility issues:

"Mark III" because this is the third genesis block for the testnet. The
  main reason for the reset is to get a more 'sane' test network; with the
  BIP16 and BIP30 and testnet difficulty blockchain rule changes the old
  testnet is a mess, with old clients serving up different, incompatible
  chains.

(Source.)
The creation of testnet2 predates the Bitcoin mailing list, but given this discussion in #bitcoin-dev, I think it happened because difficulty on testnet was too high:
17:04   slush   btw any chance to reset testnet?
17:05   tcatm   you could use your pool and a modified bitcoind to reset it in about 6 hours
17:05   slush   no, I don't want to connect pool to testnet ;)
17:06   slush   But new genesis block in next release should solve this, right?
17:07   gavinandresen   You talking about possible testnet reset?
17:08   slush   it would be nice. It's practically impossible to 'test' anything on testnet :)
17:08   gavinandresen   If you have two machines you can create your own private testnet
17:09   gavinandresen   ... but you can't test until they've generated at least 100 blocks.
17:10   slush   gavinandresen: agree, but is there any reason for keeping difficulty so high?
17:10   gavinandresen   Nope
[Edited for length.]

(Source.)


---

