<p>Nick O'Dell has it right. To expand a bit on the last question:</p>
<blockquote>
<p>What implications do blocking port 8333 have on my bitcoin daemon from getting transactions? Does it get less transactions or get transactions slower?</p>
</blockquote>
<p>It has no impact. There are only ever 8 outgoing connections even if you disable this port or set <code>listen=0</code>.
If you set <code>maxconnections=</code> significantly lower than 8, then you could (I suppose) start to have problems. If your <code>addnode=</code> or <code>connect=</code> were connecting you to a few slow/intermittent peers.</p>
<p>EDIT:</p>
<blockquote>
<p>&quot;I believe, effectively, blocking port 8333 will only stop peers from connecting to me (stops inbound) and not me connecting to peers (does not stop outbound). Is this right?&quot;</p>
</blockquote>
<p>It just occurred to me that yes if you block the port on the device hosting the node, it will be blocked. But with IPv6 now becoming more available from ISPs you can get inbound connections on 8333 even if you did not use UPNP, nor port forward on your router (many domestic routers do not support IPv6 filtering).</p>

CC BY-SA 4.0
2022-10-17T20:09:42.930Z
What happens if I addnode more than 8 outgoing peers? It keeps rotating them?
Vincent Alex
CC BY-SA 4.0
2017-04-11T06:51:23.953Z
2020-09-23T23:03:38.923Z
2020-09-23T23:03:38.923Z
Scalextrix
<blockquote>
<p>The reference here for running the bitcoin daemon does not really clarify what <code>maxconnections</code> mean.</p>
<p>Furthermore, that <code>maxconnections</code> only controls the number of inbound connections and not outbound. Is this true?</p>
</blockquote>
<p><code>maxconnections</code> counts both inbound and outbound connections. If you have 8 outbound connections, you can only have 117 inbound connections.</p>
<blockquote>
<p>Is 8 the maximum number of incoming peer connections?</p>
</blockquote>
<p>No, 8 is the maximum number of outgoing connections.</p>
<blockquote>
<p>I believe, effectively, blocking port 8333 will only stop peers from connecting to me (stops inbound) and not me connecting to peers (does not stop outbound). Is this right?</p>
</blockquote>
<p>Yes, that's correct. Also, there's a setting to do this without firewall software - set <code>listen=0</code></p>
<blockquote>
<p>What implications do blocking port 8333 have on my bitcoin daemon from getting transactions? Does it get less transactions or get transactions slower?</p>
</blockquote>
<p>That could happen in theory, but in my experience it still works pretty well.</p>

CC BY-SA 4.0
2021-11-06T10:01:30.933Z
how to reduce the # of inbound connections? outbound connections? # of peers? i try to reduce download speed
droid192
CC BY-SA 3.0
2017-04-10T23:20:53.103Z
2017-04-10T23:20:53.103Z
2020-06-16T11:10:03.350Z
Nick ODell
<p>The reference <a href="https://en.bitcoin.it/wiki/Running_Bitcoin" rel="nofollow noreferrer">here</a> for running the bitcoin daemon does not really clarify what <code>maxconnections</code> mean.</p>

<pre>
maxconnections=  Maintain at most  connections to peers (default: 125)
</pre>

<p>Is this the max connection for all inbound and outbound peer connections? Or is it just to one or the other? If I understand correctly, inbound connections are others trying to connect to your node for information (e.g. transaction) propagation, while outbound connections are your bitcoin daemon node connecting to others for information.</p>

<p>Here's <a href="https://bitcoin.stackexchange.com/questions/8109/how-does-one-attain-1-000-connections-like-blockchain-info">another reference</a> in one of the posted answers that stated 8 outbound peer connections is the max; it seems to imply that the number of outbound peer connections is unconfigurable. Furthermore, that <code>maxconnections</code> only controls the number of inbound connections and not outbound. Is this true? </p>

<p>I don't intend on being connected to by other peers (this decision is rather selfish, but that's besides the point), so I've blocked port 8333. I believe, effectively, blocking port 8333 will only stop peers from connecting to me (stops inbound) and not me connecting to peers (does not stop outbound). Is this right? </p>

<p>What implications do blocking port 8333 have on my bitcoin daemon from getting transactions? Does it get less transactions or get transactions slower? I've been noticing that for relatively long stretches of time (e.g. 20 seconds or so), sometimes I see no transactions come through.</p>

<transactions><bitcoind><unconfirmed-transactions><connection>
Is 8 the maximum number of incoming peer connections?
Jane Wayne
# Is 8 the maximum number of incoming peer connections?

(Asked by: username_0 on 2017-04-10)

The reference [here](https://en.bitcoin.it/wiki/Running_Bitcoin) for running the bitcoin daemon does not really clarify what `maxconnections` mean.

```

maxconnections=  Maintain at most  connections to peers (default: 125)

```

Is this the max connection for all inbound and outbound peer connections? Or is it just to one or the other? If I understand correctly, inbound connections are others trying to connect to your node for information (e.g. transaction) propagation, while outbound connections are your bitcoin daemon node connecting to others for information.

Here's [another reference](https://bitcoin.stackexchange.com/questions/8109/how-does-one-attain-1-000-connections-like-blockchain-info) in one of the posted answers that stated 8 outbound peer connections is the max; it seems to imply that the number of outbound peer connections is unconfigurable. Furthermore, that `maxconnections` only controls the number of inbound connections and not outbound. Is this true?

I don't intend on being connected to by other peers (this decision is rather selfish, but that's besides the point), so I've blocked port 8333. I believe, effectively, blocking port 8333 will only stop peers from connecting to me (stops inbound) and not me connecting to peers (does not stop outbound). Is this right?

What implications do blocking port 8333 have on my bitcoin daemon from getting transactions? Does it get less transactions or get transactions slower? I've been noticing that for relatively long stretches of time (e.g. 20 seconds or so), sometimes I see no transactions come through.

**Tags:** transactions, bitcoind, unconfirmed-transactions, connection


---

## 2 answers

### Answer by username_3 on 2017-04-10. Score: 5 | Accepted answer

> The reference here for running the bitcoin daemon does not really clarify what `maxconnections` mean.
>
> Furthermore, that `maxconnections` only controls the number of inbound connections and not outbound. Is this true?

`maxconnections` counts both inbound and outbound connections. If you have 8 outbound connections, you can only have 117 inbound connections.

> Is 8 the maximum number of incoming peer connections?

No, 8 is the maximum number of outgoing connections.

> I believe, effectively, blocking port 8333 will only stop peers from connecting to me (stops inbound) and not me connecting to peers (does not stop outbound). Is this right?

Yes, that's correct. Also, there's a setting to do this without firewall software - set `listen=0`

> What implications do blocking port 8333 have on my bitcoin daemon from getting transactions? Does it get less transactions or get transactions slower?

That could happen in theory, but in my experience it still works pretty well.

> **Comments:**
> **username_4**: how to reduce the # of inbound connections? outbound connections? # of peers? i try to reduce download speed  

---

### Answer by username_1 on 2017-04-11. Score: 1

username_3 O'Dell has it right. To expand a bit on the last question:

> What implications do blocking port 8333 have on my bitcoin daemon from getting transactions? Does it get less transactions or get transactions slower?

It has no impact. There are only ever 8 outgoing connections even if you disable this port or set `listen=0`.
If you set `maxconnections=` significantly lower than 8, then you could (I suppose) start to have problems. If your `addnode=` or `connect=` were connecting you to a few slow/intermittent peers.

EDIT:

> "I believe, effectively, blocking port 8333 will only stop peers from connecting to me (stops inbound) and not me connecting to peers (does not stop outbound). Is this right?"

It just occurred to me that yes if you block the port on the device hosting the node, it will be blocked. But with IPv6 now becoming more available from ISPs you can get inbound connections on 8333 even if you did not use UPNP, nor port forward on your router (many domestic routers do not support IPv6 filtering).

> **Comments:**
> **username_2**: What happens if I addnode more than 8 outgoing peers? It keeps rotating them?  

---

