Unable to add ethereum peer. Peer list is empty
ethereum
Solution
There are many reasons which could prevent the nodes to get sync-ed.
System Clocks not Sync
One of the most common but difficult-to-find reasons is that the system clocks of the devices do not sync. The nodes do not sync even if the clocks are differ by just 12 seconds.
From https://github.com/ethereum/wiki/wiki/Mining :
The difficulty dynamically adjusts so that on average one block is produced by the entire network every 12 seconds (ie., 12 s block time). This heartbeat basically punctuates the synchronisation of system state and guarantees that maintaining a fork (to allow double spend) or rewriting history is impossible unless the attacker possesses more than half of the network mining power (so called 51% attack).
The problem could be solved by using the same NTP server (preferably geographically close to the network) on all devices.
Network IDs not Matched
By using the `--networkid 12345` option on the command line, the network ID of the network is set to `12345`. Please make sure that the settings are the same among all nodes, and that the value is a random positive unsigned 32-bit number (ie. 1 ~ 2147483647). Do not use `12345`, since there may be too many people using it.
Firewall not Properly Configured
Ethereum uses TCP and UDP ports `30303` by default to communicate with each other. Please make sure that both `30303/TCP` and `30303/UDP` are not blocked by the firewall on the device.
Problem
I am trying to setup a private ethereum network. I started two nodes in the same machine (Windows 7) in two different ports. I am unable to add one node as the peer of the other node. What I have done so far is this. Start two nodes with same network id, different data dirs, and different ports. Find the node address of one node. ``` > admin.nodeInfo.enode "enode://5d272e8bee6d29dfff6313999a4a2c3d8109ae6f3eb103480f4536c0542549b9fa12a8d8ae5ebee9c4db55cab553693b04eedbc9b29f35bbc0af1956231b42b4@0.0.0.0:30303" ``` Add the node to the other peer. ``` > admin.addPeer("enode://5d272e8bee6d29dfff6313999a4a2c3d8109ae6f3eb103480f4536c0542549b9fa12a8d8ae5ebee9c4db55cab553693b04eedbc9b29f35bbc0af1956231b42b4@192.168.1.5:30303") true ``` But, if I check peer information of the second peer, it shows that it doesn't have any peers. ``` > admin.peers [] ``` Also, I tried to add the first peer as a static peer for the second node by adding node address to `data/static-nodes.json`, but still `admin.peers` returns an empty list. Does anyone know how to fix this?