Unable to connect to seed node

Question

Hi,

I've got my first server set-up. I'm just unable to connect my second server to the seed node. Below is the error I'm getting:

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MultiChain Core Daemon build 1.0 alpha 16 protocol 10003

Retrieving blockchain parameters from the seed node 10.0.2.15:5767 ...
Error: Couldn't connect to the seed node 10.0.2.15 on port 5767 - please check multichaind is running at that address and that your firewall settings allow incoming connections.
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I'm pretty sure it is not a firewall problem because:

a. I used my personal desktop with my firewall off and still got the same error

b. It worked previously (maybe about 2-3 weeks ago) with the same setup without any issue.

c. I've tried using both the alpha-15 and alpha-16 versions but end up with the same problem.

Any help is much appreciated, thanks!

Answer 1

It looks like the IP address that the first node gave you was wrong, based on its local network rather than globally accessible IP address. (MultiChain applies various heuristics to guess which IP address is the right one, but they can be wrong.) If you run ifconfig -a you should see an alternative IP address to use.

Comments

OK, thanks. Here's what we need:

a) Always run multichaind with the options -debug=mchn -debug=mchnminor -debug=net

b) Send us the pair of debug.log files (inside the individual blockchain's directory) from the two nodes for one case where it connects successfully - you can zip them to make them smaller.

c) Send us the same pair of files for one case where it connects unsuccessfully.

Using your email address on this system, I will email you the address to send the files back to.

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Thanks for sending your files. It looks like the most likely explanation is you had an old params.dat file in the blockchain directory on the second server, so you were trying to make a connection between two incompatible blockchains. Please try removing the entire ~/.multichain/[chain-name] directory on the node you are trying to connect from, then recommence the process of connecting.

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That's fixed it! :-)  Many thanks! I was unaware that you had to cull the entire ~/.multichain/[chain-name] directory each time for a new chain. Is there a FAQ / gotchas section that information can be added to please?

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Great - thanks. This Q&A is the FAQ so hopefully someone can find the information in future.

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Glad it helped me.!!