Docker issue connecting to genesis node

Question

I have "rpcallowip=0.0.0.0/0" in my multichain.conf

docker images are able to ping and netcat displays the necessary port on genesis image as open..

Any idea on why they wont talk?

https://imgur.com/a/kdDiDPG

Answer 1

First, FYI, rpcallowip is about connections to a node's JSON-RPC API, not the peer-to-peer connection between nodes. So it's not related to this issue.

Have you made any other changes to multichain.conf that might be preventing the connection?

Comments

I found a solution this morning. I used a overlay network rather than a bridged network

- "docker swarm init"

- "docker network create -d overlay --attachable --subnet 192.168.1.0/24 Multichain-Network"

- This is the network I used to connect my nodes

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OK great, thanks for the update.

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Update on this, back to no longer working.. Reverted repo back 10 hours to when it was working and still no luck..

only the ports were changed in multichain.conf

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If it was working then no longer working, it's most likely a Docker networking issue. Are you able to try this outside the Docker environment to isolate the problem?

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Yeah works perfectly fine in Virtual box with the same basic config.. Also worked on Mac yesterday

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So I'm afraid we can't give you specific help with Docker since we don't use it here. Sorry about that, please update here if you work it out.

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The issue appears to be that the genesis node is sending the paramaters to a port number that isnt open on the requesting container.

12.247928  tx=19  date=2025-03-07 14:08:48 progress=1.000000  cache=0
2025-03-07 14:09:08 mchn: Sending minimal parameter set to 192.168.1.11:52352
2025-03-07 14:09:08 socket receive timeout: 88s, peer 5
2025-03-07 14:09:08 disconnecting peer=5
2025-03-07 14:09:08 receive version message: /MultiChain:0.2.0.13/: version 70002, blocks=-1, us=192.168.1.10:6001, peer=5
2025-03-07 14:09:38 mchn: Sending minimal parameter set to 192.168.1.11:56830
2025-03-07 14:09:38 socket receive timeout: 87s, peer 6
2025-03-07 14:09:38 disconnecting peer=6
2025-03-07 14:09:38 receive version message: /MultiChain:0.2.0.13/: version 70002, blocks=-1, us=192.168.1.10:6001, peer=6

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This is the temporary port created by the requester for the outgoing connection, and doesn't accept incoming connections. It is numbered randomly so you'd not expect to recognize it.

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I booted up an ubuntu vm, now everything is working no problem with normal bridged network.. Appears to be a windows docker issue..

Follow up question, is there a way I can scrip granting access to a node trying to connect.. I have the initial creation of the chain already scripted, trying to find a way to script "multichain-cli logChain grant 174oa82Ynbyxm5ZX7V6PpE6twHy66c97q7os8b connect,send,receive"
since the code is dynamically generated each time for each node.

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Of course, that's what the JSON-RPC API is for. (When you use multichain-cli, it's actually sending an API call for you.)

https://www.multichain.com/developers/json-rpc-api/