<p>No. The nodes notify only about block height in the beginning of connection in <code>version</code> message. When node wants to notify about new block/tx it received/created, it uses <code>inv</code> message.</p>

<p>There is no point to notify other peers about downloading full blockchain. Other nodes have nothing to do with such information.</p>

CC BY-SA 4.0
2019-01-15T00:42:45.187Z
It would be useful for blockchains that have very slow blocks, ie >24 hours as -maxtipage of bitcoin 24 hours causes a bug in the blockchain where users cannot use rpc mining commands, since the code thinks it is still downloading the initial blockchain. Thanks for your answer btw
Barney Chambers
CC BY-SA 4.0
2019-01-15T00:44:35.017Z
@BarneyChambers that's interesting, but no one will use such slow blockchain
Zergatul
CC BY-SA 4.0
2019-01-15T08:00:10.297Z
this has happened to a few blockchains ;) Brazio, Octocoin to name just 2
Barney Chambers
CC BY-SA 4.0
2019-01-15T00:36:22.470Z
2019-01-15T00:36:22.470Z
Zergatul
<p>No, for the simple reason that <em>the network do not need to know when and if a node finish syncing</em> to latest block height.</p>

<p>That's irrelevant to the blockchain network so there isn't any sort of syncing complete message broadcasting.</p>

CC BY-SA 4.0
2019-01-15T11:12:41.647Z
2019-01-15T11:12:41.647Z
AG23
<p>No it doesn't broadcast a message like that. </p>

<p>Your bitcoin node doesn't know when it's fully synced. All it knows for sure is that it's up to par with all the nodes its currently connected to. </p>

<p>At any given moment, your node is working to be as synced as possible, listening to its peers. But that means you have to trust what they tell you, and trust that they are also up to date. Certainty is impossible, but the probability is pretty high (>99%) that you're up to sync when connected to several peers. The general rule is that if you connect to 8 peers, you can reach everyone. Even if a few are dishonest, the rest aren't, and all you need is one telling the truth. </p>

<p>What your node does broadcast is what services it offers, its version number, the time, and its current blockheight. </p>

CC BY-SA 4.0
2019-01-15T16:08:28.743Z
2019-01-15T16:08:28.743Z
BluJay
<p>When a bitcoin core node is fully synced, does it broadcast to the rest of the network that is has finished syncing? If yes, where in the bitcoin-core source code is this implemented?</p>

<bitcoin-core><bitcoind><synchronization>
Does a bitcoin node broadcast that it is full synced?
Barney Chambers
# Does a bitcoin node broadcast that it is full synced?

(Asked by: username_0 on 2019-01-15)

When a bitcoin core node is fully synced, does it broadcast to the rest of the network that is has finished syncing? If yes, where in the bitcoin-core source code is this implemented?

**Tags:** bitcoin-core, bitcoind, synchronization


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## 3 answers

### Answer by username_1 on 2019-01-15. Score: 2 | Accepted answer

No. The nodes notify only about block height in the beginning of connection in `version` message. When node wants to notify about new block/tx it received/created, it uses `inv` message.

There is no point to notify other peers about downloading full blockchain. Other nodes have nothing to do with such information.

> **Comments:**
> **username_0**: It would be useful for blockchains that have very slow blocks, ie >24 hours as -maxtipage of bitcoin 24 hours causes a bug in the blockchain where users cannot use rpc mining commands, since the code thinks it is still downloading the initial blockchain. Thanks for your answer btw  
> **username_1**: @username_0 that's interesting, but no one will use such slow blockchain  
> **username_0**: this has happened to a few blockchains ;) Brazio, Octocoin to name just 2  

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### Answer by username_2 on 2019-01-15. Score: 0

No, for the simple reason that *the network do not need to know when and if a node finish syncing* to latest block height.

That's irrelevant to the blockchain network so there isn't any sort of syncing complete message broadcasting.


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### Answer by username_3 on 2019-01-15. Score: 0

No it doesn't broadcast a message like that.

Your bitcoin node doesn't know when it's fully synced. All it knows for sure is that it's up to par with all the nodes its currently connected to.

At any given moment, your node is working to be as synced as possible, listening to its peers. But that means you have to trust what they tell you, and trust that they are also up to date. Certainty is impossible, but the probability is pretty high (>99%) that you're up to sync when connected to several peers. The general rule is that if you connect to 8 peers, you can reach everyone. Even if a few are dishonest, the rest aren't, and all you need is one telling the truth.

What your node does broadcast is what services it offers, its version number, the time, and its current blockheight.


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