12 votes
Accepted

How to prevent being blacklisted for running an ethereum client?

You can tell parity to avoid scanning private IPs by simply running: parity --allow-ips public You can even fine-tune parity to do less aggressive peering: parity --allow-ips public --no-discovery -...
q9f's user avatar
  • 32.9k
12 votes
Accepted

Why does Ethereum require use of UDP (and not TCP) for discovery?

UDP-based discovery is one of the main paradigms of peer discovery. For example, Universal Plug and Play (UPnP) uses the UDP-based Simple Service Discovery Protocol (SSDP), and BitTorrent has a UDP-...
Richard Horrocks's user avatar
7 votes
Accepted

How can I create connected multiple blockchains?

With Ethereum alone it's not possible (yet), unless you implement a custom solution. You should look into: raiden network: is a lightning network style transaction channel network which allows ...
q9f's user avatar
  • 32.9k
7 votes

How to prevent being blacklisted for running an ethereum client?

I had a similar problem like you. Hetzner noticed that the abuse warning was triggered because the host tried to send tpc/udp packets to private network addresses (RFC1918). In order to avoid getting ...
ivicaa's user avatar
  • 7,519
5 votes
Accepted

MetaMask cannot connect to "localhost 8545"

Yes, you need to run testRPC before connecting Metamask. Check the port that testRPC is using as well it should be 8545
dangerousfood's user avatar
4 votes

How to connect two truffle instances?

By using the same blockchain you can interact with a single contract. Make sure that the applications use the same contract address by using for example var meta = MetaCoin.at("0x1234..."). You can ...
Roland Kofler's user avatar
3 votes

Parity PoA chain not receiving transactions

I have figured this out. I was not using an --engine-signer, so no one was sealing the transactions. Once I specified this flag, I got an error saying the account was not associated with the specified ...
ethereum_alex's user avatar
3 votes

How to run JSON rpc with parity server?

I don't know if this is the correct answer, but it might be an idea. Can you map the public address to the private one with some iptables rules? I would just open one random port to the public ...
FrenchieiSverige's user avatar
3 votes
Accepted

Difficulties to start Ethereum json RPC

Insecure approach: On the remote machine run geth with the following arguments: --rpc --rpcapi "admin,personal,db,eth,net,web3" --rpcport "8080"--rpcaddr "0.0.0.0" They are detailed here, here and ...
Sebi's user avatar
  • 5,294
3 votes
Accepted

peers keep connects and disconnects into private Ethereum blockchain

https://ethereum.stackexchange.com/a/5931/4575 is answer to my question. My main problem was my local time was incorrect. "Ethereum nodes (regardless of mining) need to have an accurate time, ...
alper's user avatar
  • 8,395
3 votes

Nodes from two different networks not operable on a private blockchain

Ethereum clients use a listener (TCP) port and a discovery (UDP) port, both on 30303 by default. Which TCP and UDP ports are required to run an Ethereum client? as a firt try use the option --...
Badr Bellaj's user avatar
  • 18.8k
2 votes

How to prevent being blacklisted for running an ethereum client?

I am currently using the following UFW rules in addition to --allow-ips public ufw deny out on eth0 to 0.0.0.0/8 ufw deny out on eth0 to 10.0.0.0/8 ufw deny out on eth0 to 100.64.0.0/10 ufw deny ...
MGriesbach's user avatar
2 votes

How to prevent being blacklisted for running an ethereum client?

Run parity with these flags (as suggested by Gavin Wood): --auto-update=all --max-peers 10 --min-peers 5 --allow-ips public
Anthony Akentiev's user avatar
2 votes
Accepted

How to connect to node?

From the Ethereum help: API AND CONSOLE OPTIONS: --rpc Enable the HTTP-RPC server --rpcaddr value HTTP-RPC server listening interface (default: "localhost") --rpcport value HTTP-RPC ...
Gerbrand's user avatar
  • 271
2 votes
Accepted

Why aren't the peer-to-peer connections transitive?

If all N nodes connected to all N-1 others, that would require a lot of bandwidth and work managing all these connections. There is a whole field of research dedicated to optimal connections ...
Xavier Leprêtre B9lab's user avatar
2 votes
Accepted

What's the point of having static nodes when IP addresses keep changing?

You should only write nodes with a static IP in <datadir>/static-nodes.json. Incidentally, the enode is a way for the client to ensure it does not loop back to itself.
Xavier Leprêtre B9lab's user avatar
2 votes

How to connect two truffle instances?

To establish the connection between two applications, you need a smart contract. This smart contract will be deployed at one end . The deploying application will use it as contractname.deployed() to ...
Aniket's user avatar
  • 3,545
2 votes

How to connect to the Private BlockChain in Azure consortium

Are you trying to connect with code or with a Geth node? If you just want to connect use: $ geth attach http://[ipaddress]:8545 If you want to add a node to the Azure based blockchain you will ...
Johan Myburgh's user avatar
2 votes
Accepted

Problems of connections with we3.providers

If you are using this for learning and testing purposes, I'd suggest using testrpc which simulates Ethereum node. It's fast and runs locally so you won't encounter any connection problems at all.
Jakub Wojciechowski's user avatar
2 votes

What is the username / node ID in an enode URL?

Found some more information: https://github.com/ethereum/devp2p/blob/38d70bb9fe9badaa48ef5262e9f78641b46d1ff4/rlpx.md nodeIdĀ is the secp256k1 public key corresponding to the node's private key. ...
Lauri Peltonen's user avatar
1 vote

How to connect not local node to private Blockchain?

One of this virtual machines has connection to Internet and mapping from port 8545 from white IP to local IP address. Are you confusing the RPC port with the TCP/UDP port in your local re-mapping of ...
abattia's user avatar
  • 303
1 vote
Accepted

Is there a way to make geth only allow connections from specified nodes?

I'm not sure how deep into geth you want to go, but p2p/Server contains a property called "NetRestrict" that allows you to restrict connections to particular IP networks. cmd/bootnode/main.go is a ...
Winston Privacy's user avatar
1 vote
Accepted

Using node in local network as provider

You should allways use localhost or 127.0.0.1 when conecting to local nodes. You should be able to use a node while syncing, but the result will be outdated.
Hari GTT Psicolabis's user avatar
1 vote

Private Blockchain - Nodes Lose Connectivity

Yes, you enable tracing on the node for the sync module, like that: parity -l sync=trace This will produce a lot of noise, but you will be able to see why nodes are talking to each other, or why not....
q9f's user avatar
  • 32.9k
1 vote

Do nodes need to have static IP addresses to connect to a private blockchain?

Initially you need a new node that wants to join the network to be able to find at least one other node on the network. This means that at the time it first joins, you need there to be another node ...
Edmund Edgar's user avatar
  • 16.9k
1 vote
Accepted

Can I reboot my router while geth fast syncing?

...if I reboot my router (not closing the console with geth process) If you want to do this, ensure that you stop the geth process first, then reboot your router. If you reboot your routing while ...
Richard Horrocks's user avatar
1 vote

Connecting to an ethereum node from meteor server side

I had the same problem and finally found the solution. I followed this guide and it worked. https://github.com/ethereum/wiki/wiki/JavaScript-API#usage Web3 has to be decleared like this: var Web3 = ...
Bumblebee's user avatar
  • 1,751
1 vote

Difficulties to start Ethereum json RPC

You have to enable personal via the --rpcapi switch. Here are some switch options: --rpcapi "admin,db,eth,debug,miner,net,shh,txpool,personal,web3"
Roland Kofler's user avatar
1 vote

I'm having a problem connecting to pools

Most (all?) mining pools will not show your worker until it has generated at least 1 share. If you are CPU mining, you will probably have to wait an eternity before you get a share. CPU mining is ...
Ross Perkins's user avatar
1 vote

Add peers into a private blockchain network?

In addition to galahad's answer if you are running more instances (nodes) on the same host use distinct ports for each instance. Otherwise you'll only get one peer listening on 30303. All subsequent ...
Sebi's user avatar
  • 5,294

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