bitcoin-qt falls back to 8 connections after some time

[T-rage_11]

I use bitcoin-qt 0.8.3 on LUBUNTU 13.04 in virtualbox.
It works very well. My router is forwarding the port 8333 to Lubuntu and after launching bitcoin-qt it takes only 1 minute to get over 8 connections.
But when I let bitcoin-qt open for some hours (overnight) because I want to run a bitcoin-node then it falls back to 8 connections!

I think this problem occurred with 0.8.1 or something .. i don't know.. maybe the problem was my last big Lubuntu-upgrade from 12.04 to 13.04 or something like that

I hope someone has an idea whats wrong?

Currently it's impossible to run a bitcoin-node

Edit: Could it be that my ISP (Telekom Austria) is blocking the port after some time because I get too many connections and traffic? I have 12Mbit download and 1Mbit upload speed. But I think that it worked a few months ago.

[pvtbrutus]

You absolutely sure the forwarded port goes to the node? Sometimes assigned IP adresses can change when you are using DHCP.

[T-rage_11]

You absolutely sure the forwarded port goes to the node? Sometimes assigned IP adresses can change when you are using DHCP.

Yes, I use static IP in Lubuntu.

[grue]

On my DSL connection, if my ip gets changed (usually pppoe reset), the connection count will drop to 8. Probably has something to do with the client not updating its external IP. The only real solution is to prevent your internet from dropping out. If you think your ISP is blocking bitcoin, an external port scan on TCP 8333 should tell if it's really the case.

[T-rage_11]

On my DSL connection, if my ip gets changed (usually pppoe reset), the connection count will drop to 8. Probably has something to do with the client not updating its external IP. The only real solution is to prevent your internet from dropping out. If you think your ISP is blocking bitcoin, an external port scan on TCP 8333 should tell if it's really the case.

external port scan result on TCP 8333: OPEN !

I have a dynamic IP. It changes every 24 hours. Probably this happens every night and this causes the drop. Maybe someone can forward this problem to a developer? An IP detection every 10 minutes or so would help every user with a dynamic IP ! 

[deepceleron]

On my DSL connection, if my ip gets changed (usually pppoe reset), the connection count will drop to 8. Probably has something to do with the client not updating its external IP. The only real solution is to prevent your internet from dropping out. If you think your ISP is blocking bitcoin, an external port scan on TCP 8333 should tell if it's really the case.

That appears correct, the code in net.cpp GetMyExternalIP seems only to be called upon startup. External IPs changing on an always-on connection should only affect a few users, perhaps a command line option to enable periodic polling of external IP would be the solution, so not everyone is hammering external IP service providers unnecessarily by default.

[dunand]

I have the same problem. I drop to 8 connections when my external IP change. After that I need to manually restart bitcoind to help the network. I sure something can be done about that.

[romerun]

Has this problem been fixed ? According to  a recent article on coindesk, 1000 of nodes disappear every night, IP address changing could contribute to the loss of nodes.

[shorena]

Has this problem been fixed ? According to  a recent article on coindesk, 1000 of nodes disappear every night, IP address changing could contribute to the loss of nodes.

I dont think this is fixed yet, but I cant test it, since I dont get disconnected by my ISP.

The article you mention would be this http://www.coindesk.com/bitcoin-nodes-need/ I guess.
These nodes disappear because people turn their computers off and not because their ISPs change the IP.

As these charts suggest https://getaddr.bitnodes.io/dashboard/
this is indeed a minor problem.

-snip-
External IPs changing on an always-on connection should only affect a few users, perhaps a command line option to enable periodic polling of external IP would be the solution, so not everyone is hammering external IP service providers unnecessarily by default.

There seem to be several discussions going on about a possible solution.
You can reach most of them from here:
https://github.com/bitcoin/bitcoin/pull/3088

A possible workaround would be a cronjob that restarts bitcoin core every x hours.