Making an RPC request from another machine on the same network

Question

I have a machine (A) running a Tezos node, with RPC port set to 8732. Its local IP is 192.168.1.200.

I have another machine (B), from the same network, from which I'd like to connect to the RPC of A.

On machine A I opened port 8732:

sudo iptables -A INPUT -p tcp --dport 8732 -j ACCEPT
sudo /sbin/iptables-save

Now, machine B should be able to do an RPC connection like this:

tezos-client --endpoint http://192.168.1.200:8732 rpc get /chains/main/blocks/head/protocols

But what it gets is:

Warning:
  Failed to acquire the protocol version from the node
  Rpc request failed:
     - meth: GET
     - uri: http://192.168.1.200:8732/chains/main/blocks/head/protocols
     - error: Unable to connect to the node: "Unix.Unix_error(Unix.ECONNREFUSED, "connect", "")"

Error:
  Rpc request failed:
     - meth: GET
     - uri: http://192.168.1.200:8732/describe/chains/main/blocks/head/protocols?recurse=no
     - error: Unable to connect to the node: "Unix.Unix_error(Unix.ECONNREFUSED, "connect", "")"

What did I do wrong? Do I have to set up a web server (nginx?) to handle the incoming HTTP request?

Answer 1

Verify the RPC is running by doing this on machine A

curl http://192.168.1.200:8732/chains/main/blocks/head/protocols

If that does not return, then you don't have the RPC setup correctly. If that does return, next step is to verify B -> A. Can you ping A from B? If not, network issue. If you can, disable iptables completely on A and try to use the client again from B. If that works, then your iptables are not correct. Make sure selinux is disabled/permissive on A too.

Answer 2

I found that this answer was the solution.

Basically I run the node on machine A using --rpc-addr 0.0.0.0 instead of localhost or 127.0.0.1.