<p>I'm trying to connect to a local testnet3 node with a custom Rust code.</p>
<p>After handshake, node sends a <code>sendcmpct</code> message as per BIP152.
The message I receive is</p>
<p><code>[11, 17, 9, 7, 115, 101, 110, 100, 99, 109, 112, 99, 116, 0, 0, 0, 9, 0, 0, 0, 233, 47, 94, 248]</code></p>
<p>where</p>
<p><code>11, 17, 9, 7</code> is the network</p>
<p><code>115, 101, 110, 100, 99, 109, 112, 99, 116, 0, 0, 0</code> is the command (12 bytes)</p>
<p><code>9, 0, 0, 0</code> is the length of the contained payload (little-endian)</p>
<p>and <code>233, 47, 94, 248</code> is the checksum.</p>
<p>There is no other bytes in the message.</p>
<p>I'm also verified that the checksum is correct.</p>
<p>Why the message declare a 9 bytes payload (correctly, as per BIP) but no real payload in the message?</p>
<p>Thanks for any help.</p>

CC BY-SA 4.0
2024-05-13T22:13:53.550Z
What software are you talking to? This sounds broken.
Pieter Wuille
CC BY-SA 4.0
2024-05-14T20:02:47.567Z
Sorry, my fault. Reading the socket, I was reusing the same buffer and truncating it again and again.
Nicola Fiorillo
CC BY-SA 4.0
2024-05-16T08:56:37.833Z
I’m voting to close this question because the author realised they had made a programming error.
RedGrittyBrick
<network><p2p><compact-blocks>
sendcmpct message
Nicola Fiorillo
# sendcmpct message

(Asked by: username_0 on 2024-05-13)

I'm trying to connect to a local testnet3 node with a custom Rust code.

After handshake, node sends a `sendcmpct` message as per BIP152.
The message I receive is

`[11, 17, 9, 7, 115, 101, 110, 100, 99, 109, 112, 99, 116, 0, 0, 0, 9, 0, 0, 0, 233, 47, 94, 248]`

where

`11, 17, 9, 7` is the network

`115, 101, 110, 100, 99, 109, 112, 99, 116, 0, 0, 0` is the command (12 bytes)

`9, 0, 0, 0` is the length of the contained payload (little-endian)

and `233, 47, 94, 248` is the checksum.

There is no other bytes in the message.

I'm also verified that the checksum is correct.

Why the message declare a 9 bytes payload (correctly, as per BIP) but no real payload in the message?

Thanks for any help.

**Tags:** network, p2p, compact-blocks

> **Comments:**
> **username_1**: What software are you talking to? This sounds broken.  
> **username_0**: Sorry, my fault. Reading the socket, I was reusing the same buffer and truncating it again and again.  
> **username_2**: I’m voting to close this question because the author realised they had made a programming error.  

---

## 0 answers

