Corona Proxy

Open the "Settings" application via "Start" and go to "Network and Internet". Here, in the "Proxy" section, find the "Manual Proxy Configuration" column. Move the slider to "On" and carefully enter the IP address and port of the proxy, then click "Save".

If you want to check the proxy's regionality, use a tool such as the proxy checker. You can either download the program or use it online. To perform the check, which allows you to determine not only the country and city, but also a number of other important indicators, you need to enter your username and password in the appropriate fields.

UDP Hole Punching is a technique used to establish a connection between two devices behind NAT (Network Address Translation) firewalls. It works by exploiting the fact that some UDP packets can still pass through the NAT firewall even if the source and destination ports are the same. However, UDP Hole Punching does not always bypass NAT for several reasons:

1. Symmetric NAT: In symmetric NAT, both the source and destination ports are translated, and the NAT firewall maintains a table of active connections. If the table is not updated correctly, UDP hole punching may not work.

2. Unstable NAT: Some NAT firewalls are known to be unstable, causing them to drop packets or change their behavior unexpectedly. This can lead to failure in establishing a connection using UDP hole punching.

3. Firewall rules: Some NAT firewalls have strict rules that prevent UDP hole punching from working. For example, if the firewall is configured to block all incoming UDP traffic, UDP hole punching will not be successful.

4. Timeout: NAT firewalls have a timeout for their connection tables. If the timeout occurs before the connection is established, UDP hole punching will fail.

5. Network congestion: If the network is congested, packets may be dropped or delayed, causing UDP hole punching to fail.

In summary, while UDP hole punching can be an effective technique for bypassing NAT, it does not always guarantee a successful connection due to various factors such as NAT behavior, firewall rules, and network conditions.

In Qt, you can use the QUdpSocket class to handle incoming UDP packets and the QDataStream class to parse the QByteArray into a bitfield structure. Here's an example of how to accept and parse a UDP QByteArray into a bitfield structure in Qt:

1. First, create a structure to represent the bitfield:

struct Bitfield {
    unsigned int field1 : 8;
    unsigned int field2 : 8;
    unsigned int field3 : 8;
    unsigned int field4 : 8;
};

2. Next, create a QUdpSocket object and bind it to a specific port:

QUdpSocket udpSocket;
if (!udpSocket.bind(QHostAddress::Any, 12345)) {
    qDebug() << "Failed to bind UDP socket:" << udpSocket.errorString();
    return;
}

3. In the readyRead() slot, accept incoming UDP packets and parse the QByteArray:

void MyClass::handleIncomingDatagram() {
    QByteArray datagram = udpSocket.receiveDatagram();
    QDataStream dataStream(&datagram, QIODevice::ReadOnly);

    Bitfield bitfield;
    dataStream >> bitfield;

    // Process the bitfield structure as needed
    qDebug() << "Received bitfield:" << bitfield.field1 << "," << bitfield.field2 << "," << bitfield.field3 << "," << bitfield.field4;
}

4. Finally, connect the readyRead() signal to the handleIncomingDatagram() slot:

connect(&udpSocket, &QUdpSocket::readyRead, this, &MyClass::handleIncomingDatagram);

In this example, the handleIncomingDatagram() slot is called whenever a new UDP packet is received. The slot accepts the incoming datagram, parses it into a bitfield structure using QDataStream, and processes the bitfield as needed.

Make sure to include the necessary headers in your code:

#include 
#include 
#include 
#include 

This example assumes that the incoming UDP packet contains exactly 4 bytes, which is enough to store the bitfield structure. If the packet contains more data, you'll need to handle it accordingly.

In data centers, proxies are used to provide IP to virtual servers. After all, one server there can be used by a dozen users at the same time. And each needs to be allocated its own IP and port. All this is done through proxies.