Try to run vrpoxy on Contabo VPS

[juhacz]

I want to switch my VPS server from Alwyzon to Contabo. With Contabo, I get a VPS server with significantly more resources for the same price. I've been successfully using Vproxy on Alwyzon for a while now, obtaining a random IPv6 address via http://user-session-xxx:pass@127.0.0.1:1080.
Unfortunately, the program doesn't work properly on Contabo.

My VPS is configured to use IPv6, and pinging IPv6 services works.
When I run

for i in {10..15}; do
ip -6 addr add xxxx:c207:2293:8873::$i/64 dev eth0
done

for i in {10..15}; do
echo "Testing ::$i"
curl -6 -s --interface xxxx:c207:2293:8873::$i https://ifconfig.co/ip
done

All addresses are working correctly.

When I run

vproxy run auto -u abc -p abc
curl -x http://abc:abc@127.0.0.1:1080 https://ifconfig.co/ip
or
curl -x http://abc-session-xx:abc@127.0.0.1:1080 https://ifconfig.co/ip

I get:

xxx:c207:2293:8873::15 (not xxx:c207:2293:8873::1, which is rather strange)
no matter what number I use instead of xx,

in the logs:

2025-11-29T13:46:33.324060Z INFO vproxy::server::http: [HTTP] 127.0.0.1:40548 -> www.yyyyyy.fi:443 forwarding connection
2025-11-29T13:46:33.329126Z INFO vproxy::connect: [TCP] connect [yyyu:4700::6812:bc6]:443 via [xxxx:c207:2293:8873::15]:48932

If I run

vproxy run -i xxx:c207:2293:8873::/64 auto -u abc -p abc
curl -x http://abc-session-2:abc@127.0.0.1:1080 https://ifconfig.co/ip
curl: (35) Recv failure: Connection reset by peer

in the kig:

2025-11-29T13:58:12.293619Z INFO vproxy::server::http: [HTTP] 127.0.0.1:53800 -> www.yyyyyy.fi:443 forwarding connection

What could be causing Vproxy not to work properly on Contabo VPS?

Best regards

[0x676e67]

There are too few details for a proper assessment. Your usage of this is completely meaningless in terms of using the session. This will use the system's default network exit.

vproxy run auto -u abc -p abc
curl -x http://abc:abc@127.0.0.1:1080 https://ifconfig.co/ip
or
curl -x http://abc-session-xx:abc@127.0.0.1:1080 https://ifconfig.co/ip

So regarding the result: xxx:c207:2293:8873::15 (not xxx:c207:2293:8873::1), which is rather strange), this is not at all surprising. This is the behavior of your system.

[juhacz]

On the Alwyzon server, where the vproxy is running, I have the server running perfectly using
reboot vproxy restart --bind 0.0.0.0:1080 -i xxxx:yyyy:105:8ae0::/64 http -u abc -p abc
I'm using sessions there, but unfortunately, it doesn't work on Contabo.

I should also mention that on the Contabo server, I can't simply use the command ping6 -I xxxx:c207:2293:8873::11 google.com or ping6 -I xxxx:c207:2293:8873::12 google.com

because it doesn't work, only after running

for i in {10..15}; do
ip -6 addr add xxxx:c207:2293:8873::$i/64 dev eth0
done

I can use ping6 -I xxxx:c207:2293:8873::11 google.com and then I get a ping response.

Additionally, after restarting the VPS, the IP addresses added through loops disappear. I tried to solve the problem using AI; I'm not a very advanced Linux user, especially in network and routing configuration. Unfortunately, the conclusion was that Contabo most likely doesn't allow, like Alwyzon, the use of IP addresses before assigning them to an interface, so a vproxy with a session connection won't work.
I use session to generate a cookie on the server, and then with this cookie, I can retrieve data from the website until the cookie expires.
I wrote to Contabo support about this, but I haven't received a response yet.

[0x676e67]

Your subnet does not support routing. This is the only explanation I can come up with.

[0x676e67]

Some providers do offer some available subnets, but they do not provide routing. Therefore, you will need to manually add the address bindings one by one.