4.0 Binding errors unless using -Djava.net.preferIPv4Stack=true

[jkister]

• OS and version

Java 21.0.9 (64 bit)
  Eclipse Adoptium
c:\program files\biglybt\jre

SWT v4968r13, win32, zoom=100, dpi=96
Windows 10 v10.0, amd64 (64 bit)
B4.0.0.1_B07/4 az3 en

• BiglyBT Version Number
  4.0.0.0 and 4.0.0.1_B07
• For *nix: Desktop Environment
  n/a

I get tracker and update errors when using interface binding with ProtonVPN:
Scrape Error: Cannot assign requested address: getsockopt
BiglyBT Core, Failed to check for core update, Cannot assign requested address: getsockopt

The checkboxes for Check bind IP Address/interfaces and Enforce IP bindings are checked.
I tried binding to the interface with ip address 10.2.0.2 and a regex like (WireGuard\sTunnel)

I am able to fix it by adding -Djava.net.preferIPv4Stack=true to %APPDATA%\BiglyBT\java.vmoptions

[parg]

Do the ProtonVPN setup instructions for BiglyBT tell you to enable the "prefer IPv4 stack" option (removed in BiglyBT 4.1 beta versions)? There used to be a hack we could use to set that option in the Java runtime but the hack can't be made to work in more recent Java versions.

Out of interest do all the failing trackers have IPv6 addresses (DNS type AAAA records)?

[jkister]

Do the ProtonVPN setup instructions for BiglyBT tell you to enable the "prefer IPv4 stack" option (removed in BiglyBT 4.1 beta versions)? There used to be a hack we could use to set that option in the Java runtime but the hack can't be made to work in more recent Java versions.

No, and in fact protonvpn support was not helpful and asked only if i could install qBittorrent and try binding which worked. when they learned it worked they were pretty done.

Out of interest do all the failing trackers have IPv6 addresses (DNS type AAAA records)?

No. One of them is tracker.biglybt.com, i dont see aaaa on it.

s1$ dig +short @ns-79.awsdns-09.com tracker.biglybt.com aaaa 
s1$ 

FYI the ipconfig looks like:

Unknown adapter ProtonVPN:

   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : WireGuard Tunnel
   Physical Address. . . . . . . . . :
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes
   IPv4 Address. . . . . . . . . . . : 10.2.0.2(Preferred)
   Subnet Mask . . . . . . . . . . . : 255.255.255.255
   Default Gateway . . . . . . . . . : 0.0.0.0
   DNS Servers . . . . . . . . . . . : 1.1.1.1
                                       1.0.0.1
                                       8.8.8.8
                                       10.2.0.1
   NetBIOS over Tcpip. . . . . . . . : Enabled

IPv6 support is disabled in the protonvpn advanced settings. IPv6 is also not enabled on any of my pc's ethernet adapters.

[parg]

Did it work prior to 4.0?

Are you using a vanilla ProtonVPN install or have you configured it in any way?

I don't really want to have to sign up for their paid version and the free version is too limited to really test anything.

I guess I could look into an easier way to configure the "java.net.preferIPv4Stack=true". Then again, if it doesn't affect all ProtonVPN ( or perhaps WireGuard based VPNs) maybe Wiki advice would suffice.

[jkister]

Did it work prior to 4.0?

Yes, sometime in version 3, but i dont remember what version :( I tried down-grading to 3.8 and it was still failing. but when i tried downgrading to 3.6 biglybt wouldnt start right and i abandoned the idea of finding an older version that worked. i upgraded from an older version of 3 to 4 and that's when it broke.

Are you using a vanilla ProtonVPN install or have you configured it in any way?

It's configured to use Split Tunneling with only BiglyBT.exe included. i also use custom dns servers 1.1.1.1/1.0.0.1 instead of their 10.2.0.1. and port forwarding is enabled. the rest is stock.

I don't really want to have to sign up for their paid version and the free version is too limited to really test anything.

It's possible their business product's free trial includes the p2p support. Looks like it does but not sure.

I guess I could look into an easier way to configure the "java.net.preferIPv4Stack=true". Then again, if it doesn't affect all ProtonVPN ( or perhaps WireGuard based VPNs) maybe Wiki advice would suffice.

Yeah that'd be helpful, I would have found that since i actually did a lot of looking/investigating. to make more obvious, maybe a popup or extra note below connection settings -> advanced -> bind to local ip with something like "check wiki for details if this doesn't work as expected".