I have another n00b question... sorry about that :(

I'm trying to deploy a smart contract to Ropsten. I have synched the Ropsten network with geth --testnet --fast --rpc --rpcapi eth,net,web3,personal, and it looks perfectly up to date.

Then I try to deploy that smart contract (which I've already deployed to my private testrpc network and it works poerfectly) to Ropsten. To do so I'm executing truffle migrate --network ropsten and I'm getting this pesky error:

Could not connect to your Ethereum client. Please check that your Ethereum client:
    - is running
    - is accepting RPC connections (i.e., "--rpc" option is used in geth)
    - is accessible over the network
    - is properly configured in your Truffle configuration file (truffle.js)

The geth instance is in fact up and running, since I can connect to it with geth attach and it works fine. It is accepting connections, since I used the --rpc option. It is accessible over the network because I've already accessed it... and I think than my Truffle configuration file is ok, here's how it looks:


module.exports = {
  networks: {
    development: {
      host: 'localhost',
      port: 8545,
      network_id: '*' // Match any network id
    ropsten: {
      host: "localhost",
      port: 8545,
      network_id: "3",

Can anyone please tell me why am I getting this error and what can I do to fix it?

Thank you so much in advance!!! :)


2 Answers 2


When I was deploying my contract through truffle in rinkeby network I too got the same error after adding from address and gas it got deployed. Try this

networks: {
  ropsten: {
    network_id: 3,
    host: '',
    port: 8545,
    gas: 4000000,
    from: <your unlocked ropsten account address>
  • Thanks a lot, Jazz! Well, looks a bit better, now I get this 2 new lines, but still it fails :( --->Using network 'ropsten'. --->Running migration: 1_initial_migration.js Could not connect to your Ethereum client (etc...)
    – JaVinci
    Sep 14, 2017 at 8:17
  • Ok, looks like the problem might be that my blockchain database has been corrupted, so I need to synchronize again... Aaaarrgghhh!!
    – JaVinci
    Sep 14, 2017 at 9:01
  • It finally worked, thanks a lot!! :) It's important to note that the only contents of truffle.js must be what you wrote... I had to remove another network I had configured in that file so this whole thing could work.
    – JaVinci
    Oct 3, 2017 at 8:33
  • You could also use following command to specifically use a network, if you have multiple networks configured. truffle migrate --network ropsten Oct 27, 2017 at 13:03

It's hard to get your ropsten account unlocked. You might opt for private key deployment. I've build lib for something like this.

const etherlime = require('etherlime');

const ICOTokenContract = require('./build/contracts/ICOToken.json');

const randomAddress = '0xda8a06f1c910cab18ad187be1faa2b8606c2ec86';

const defaultConfigs = {
    gasPrice: 20000000000,
    gasLimit: 4700000

const deployer = new etherlime.InfuraPrivateKeyDeployer('Your Privste KEY', 'ropsten', 'Your infura API key', defaultConfigs);

const runICODeployment = async () => {
    const contractWrapper = await deployer.deploy(ICOTokenContract);
    const transferTransaction = await contractWrapper.contract.transferOwnership(randomAddress);
    const result = await contractWrapper.verboseWaitForTransaction(transferTransaction.hash, 'Transfer Ownership');

Place this in a simple js file and run it with node. Hope this helps.

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