Please don't connect to the network if your firewall doesn't allow other to connect to port 30303

accapeaccape Member Posts: 66
If you do connect, every other client will freeze for several minutes trying to connect to your node. (because there is no timeout and everything is single-threaded)
Post edited by StephanTual on


  • techmixtechmix Member Posts: 1
    exactly, it's so annoying
  • accapeaccape Member Posts: 66
    The issues has now been fixed in upstream. Update your git repositories.
  • arckearcke Member Posts: 34
    I did. Now the blockchain db is corrupt. Is it enough to delete the .ethereum/blocks directory to repair a corrupt blockchain?
  • MilanMilan San Diego, CAMember Posts: 46
    Is this like the bitcoin-QT client issue where you have to set up port forwarding at your router in order to be a "full" client? Only for bitcoin-QT it's port 8333:
  • accapeaccape Member Posts: 66
    Yes, forgot to add if you are behind a router you need to port forward as well. But the timeout is fixed now, so at least you aren't blocking other clients anymore if you don't.
  • MilanMilan San Diego, CAMember Posts: 46
    I set up my router to forward port 30303 to my linux machine, but still can't seem to connect to any peers, and I core dump when I try.

    I get: WARNING: Couldn't punch through NAT ..... what(): std::bad_cast Aborted (core dumped)

    Each day I do seem to make a tiny bit of progress, but never enough...

    I can hit "mine" without crashing alephzero, but hitting "Connect" crashes the client. Same WARNING, followed by

    terminate called after throwing an instance of 'boost::exception_detail::clone_tmpl >'
    what(): resolve: No such file or directory
  • MilanMilan San Diego, CAMember Posts: 46
    edited February 2014
    I set my router to forward port 30303 to my PC.

    I set Virtualbox to forward port 30303 to my virtual ubuntu installation.

    Anything else? I entered "" into the dialog that popped up when I clicked Connect in alephzero.

    That first peer showed up in the left pane of alephzero. But once I saw other connection attempts start scrolling by in the terminal window, my alephzero client goes grey and stops responding. Am I supposed to wait this out, or is something wrong?
  • comtechnetcomtechnet Member Posts: 57
    I recommend that Corp Ethereum perform a "loop back test" on each connection attempt and verify that an external computer (the corp ethereum network or a peer) can respond back thru the connection "attempt" port and either allow the connection or reject the connection with the appropriate explanation.

    For example - my router does do uPNP and appears to have created the appropriate portmap table entry when I fired up the GUI (AlephZero). But I am assuming everything is good - and by the terminal activity, it appears things got off to a good start - but now after a flurry of activity - everything is quiet - no additional messages - the last entry in my terminal is "Sending 0 blocks from 2 to 2 Parent: long addr string"

    Another recommendation:

    The AlephZero "Mine" button goes from regular to dim after you click it, so you can't tell what it is doing or suppose to be doing. I recommend you put some kind of msg with the click.

    I'm unsure what to do from here.
  • Wil611Wil611 Member Posts: 77 ✭✭
    @Milan I have a similar issue in that I managed to install VirtualBox and got the client to compile and run but am having issues connecting to peers. I am new to Virtualbox not sure I'm configuring port forwarding correctly. The client mines with out problem but when I try to connect to peers I get the following error on the terminal window.

    [email protected]:~/ether/cpp-ethereum-build$ ./alethzero/alethzero
    Opened blockchain db. Latest: 3ec579127ce968eead93cfd4f1da108c5dee7d0bec5626a39261b6e5a54e60a4
    *** State root: fb92e53e8bba8530349d6999a31e7bb900c856dc09e87a82ac4b66b08e59af0e
    *** Genesis hash: 75806a65707043a9b46156bfc6f931635759398c0737a2e211a58c1a69c215bc
    Address: = [LOCAL]
    Address: = [PEER]
    *** UPnP device not found.
    Listening on local port 30303 (public:
    Mode: Full
    Initialising: latest=3ec579127ce968eead93cfd4f1da108c5dee7d0bec5626a39261b6e5a54e60a4
    Attempting connection to
    Connected to
    37 | ERROR: std::exception

    Any ideas?
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