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Bitcoin => Development & Technical Discussion => Topic started by: dadach on September 20, 2018, 11:05:24 AM



Title: bitcoin core client blocked on my network
Post by: dadach on September 20, 2018, 11:05:24 AM
Hi, on my residence network, I cannot run Bitcoin Core, until I fire up VPN. Then the blocks are syncing and the transactions are showing up. Is there a way to configure the client to somehow connect, or once it is blocked in firewall, there is no way around it? Litecoin client works without a problem.
Thanks for helping!


Title: Re: bitcoin core client blocked on my network
Post by: bob123 on September 20, 2018, 11:35:29 AM
The answer to your question is already included in your post. A VPN.

If the firewall is set to reject/drop specific packets (in this case: any bitcoin traffic), the only way to bypass this is to hide the packets (e.g. through encryption).
When using a VPN, you are encrypting your traffic. The firewall just sees the source/destination, but doesn't see any payload.
This way the firewall can't tell what kind of packets these are. And if it is configured to drop bitcoin-related traffic, simple encrypted payload to an unknown IP address won't be dropped.

If you don't have access to the firewall configuration, using a VPN is the easiest way to circumvent this.


Title: Re: bitcoin core client blocked on my network
Post by: ABCbits on September 20, 2018, 11:42:29 AM
There are few options including :
1. Change bitcoin default open port. Your ISP might block default Bitcoin Core port, whether it's intentional or not[a]
2. Make sure your Bitcoin Core comes from legitimate source
3. Check if your PC's firewall block connection made by Bitcoin Core or any software outside it's whitelist

But using VPN (or other forms of secure connection) is more convenient and could protect your privacy/anonymity.

a. https://www.ccn.com/isps-intentionally-blocking-bitcoin/ (https://www.ccn.com/isps-intentionally-blocking-bitcoin/)


Title: Re: bitcoin core client blocked on my network
Post by: aleksej996 on September 20, 2018, 12:50:58 PM
I don't know what is the popularity with VPN these days.
They don't offer you good privacy, since the VPN provider will know your identity,

Just install Tor, it is free, it gives you real anonymity and you can even accept inbound connections without messing with the router and port forwarding, just by running Bitcoin Core with "-listenonion" argument.


Title: Re: bitcoin core client blocked on my network
Post by: bob123 on September 21, 2018, 06:50:40 AM
I don't know what is the popularity with VPN these days.
They don't offer you good privacy, since the VPN provider will know your identity,

Did you read the OP ? It is not about privacy here. It is about BEING ABLE to connect to the bitcoin network.
OP never mentioned he wants enhanced privacy.

Additionally, anyone can see traffic to/from the bitcoin network. With a VPN, noone except you and the VPN provider knows that YOU are connecting to the BTC network.
So.. it does increase privacy. Even if that wasn't the intention of OP.



Just install Tor [...]

Why should he use TOR? It is WAY slower. It is just not worth the hassle if you don't insist on hiding the traffic from the VPN provider (which OP isn't).
TOR might be helpful in some situations, but it is NOT a panacea for everything.


Title: Re: bitcoin core client blocked on my network
Post by: dadach on September 21, 2018, 08:04:17 AM
thanks, I do not want to run VPN 24/7, as it is my online gaming computer :)

I will try the port changing option.


Title: Re: bitcoin core client blocked on my network
Post by: bob123 on September 21, 2018, 09:11:53 AM
I do not want to run VPN 24/7, as it is my online gaming computer :)

You can configure your system to only route the bitcoin traffic through the VPN, leaving each other traffic untouched.
Unfortunately this isn't that trivial, but you can use different interfaces for different ports (i.e. 1 interface only for bitcoin port -> VPN).

Changing ports, of course, is the easier way. If only ports are blocked, thats perfectly fine.
But if the firewall does inspect the packets, the only possibility is to obscure the payload (through VPN, SSH tunneling, etc..).


Title: Re: bitcoin core client blocked on my network
Post by: dadach on September 21, 2018, 10:36:25 AM
I do not want to run VPN 24/7, as it is my online gaming computer :)

You can configure your system to only route the bitcoin traffic through the VPN, leaving each other traffic untouched.
Unfortunately this isn't that trivial, but you can use different interfaces for different ports (i.e. 1 interface only for bitcoin port -> VPN).

Changing ports, of course, is the easier way. If only ports are blocked, thats perfectly fine.
But if the firewall does inspect the packets, the only possibility is to obscure the payload (through VPN, SSH tunneling, etc..).

I have a WIFI dongle at home. Could that work, or do I need to install a separate NIC?

Also LTC and DOGE core clients work without a problem.


Title: Re: bitcoin core client blocked on my network
Post by: aleksej996 on September 21, 2018, 11:55:21 AM
I don't know what is the popularity with VPN these days.
They don't offer you good privacy, since the VPN provider will know your identity,

Did you read the OP ? It is not about privacy here. It is about BEING ABLE to connect to the bitcoin network.
OP never mentioned he wants enhanced privacy.

Additionally, anyone can see traffic to/from the bitcoin network. With a VPN, noone except you and the VPN provider knows that YOU are connecting to the BTC network.
So.. it does increase privacy. Even if that wasn't the intention of OP.



Just install Tor [...]

Why should he use TOR? It is WAY slower. It is just not worth the hassle if you don't insist on hiding the traffic from the VPN provider (which OP isn't).
TOR might be helpful in some situations, but it is NOT a panacea for everything.

I'm just talking about why VPN shouldn't be as popular as it is, not just for OP.
Tor is perfect for censorship resistance. You can't be guaranteed that your VPN will not mess with your connection to the Bitcoin network or that your ISP will not block access to your VPN or all VPN traffic for that matter.

Tor is simply a lot better then VPN in pretty much every aspect that is needed by the wider population.
There are some use cases for VPN, but to avoid censorship or increase privacy, it is quite a stupid choice compared to using Tor.

As for the speed, for Bitcoin purposes, I don't think it is significant. If you want to watch videos online, sure, but otherwise use Tor.

Now I will be honest, I know why VPN is more popular then Tor. It is the same reason why Windows is more popular then Linux.
You don't see Tor advertising it self on youtube videos and stuff. Nobody earns money when you use Tor, it is free, open source, that is the point.

VPN tech is good for some purposes, but nowadays they are commercialized, sold to people when they don't need it.
Most VPNs should be run by people that use them, most VPNs shouldn't be for open access by people that don't know and don't trust each other.

That is all I am saying.

If you want to run Bitcoin over a some network, run it over Tor, not a VPN.
Unless you have some specific purpose for your traffic to be routed over some specific network, you don't need and shouldn't use VPN.


Title: Re: bitcoin core client blocked on my network
Post by: piotr_n on September 21, 2018, 01:28:25 PM
Hi, on my residence network, I cannot run Bitcoin Core, until I fire up VPN. Then the blocks are syncing and the transactions are showing up. Is there a way to configure the client to somehow connect, or once it is blocked in firewall, there is no way around it? Litecoin client works without a problem.
Thanks for helping!
Unfortunately it is very easy to block bitcoin core as it practically refuses to connect to any other TCP port than 8333.

There are some servers using a different port number, but you'd have to patch your own node to connect to them.


Title: Re: bitcoin core client blocked on my network
Post by: dadach on September 22, 2018, 06:25:20 AM
Solution:

Installed WIFI dongle, used ForceBindIP to bind the bitcoin-qt to the WIFI adapter address, in mikrotik connected the address to the VPN.

the node works now :)