When faced with network restrictions, blocked IPs, or the need to update access credentials, you might consider changing your VPS's IP address. While VPS server IPs are generally assigned by the service provider and are relatively fixed, it's possible to "quickly switch" the access IP, thereby improving the network environment. This can be achieved primarily by changing the VPS's public IP address, using a proxy gateway, or configuring multiple IP exits.

Core Idea: Understanding the Essence of IP Switching

First, it's crucial to understand that for an already deployed VPS, the primary public IP address on its main network interface card (NIC) is usually assigned and bound by the service provider and cannot be changed arbitrarily or cost-free within the VPS. "Quickly switching IPs" typically refers to the following three approaches:

Changing the Underlying Public IP: Using the service provider's API or console, you can give the VPS instance a completely new public IP address. This involves restructuring the underlying network configuration, and the VPS usually needs to be restarted.

Adding Multiple Secondary IPs (Multiple IP Exits): Configuring multiple public IPs for the VPS NIC and then using routing rules to direct specific traffic from specific IPs. This is the method closest to the concept of "switching."

Using a proxy or gateway for redirection: This method doesn't change the VPS's own IP address, but instead redirects all outbound network traffic through a third-party proxy server or gateway, which provides a variable exit IP.

We will introduce specific and feasible operational methods based on these three approaches.

Method 1: Changing the Elastic Public IP via the service provider's API (Most thorough)

Most mainstream cloud service providers offer "Elastic Public IP" services. This IP resource is independent of the VPS instance and can be bound to or unbound from the instance at any time.

The typical process is: apply for a new Elastic Public IP in the cloud console; unbind the current public IP of the original VPS instance (it will usually be released); bind the newly applied Elastic Public IP to the VPS instance; the VPS instance may need to restart network services or perform minor configurations. This process can be automated through the API provided by the cloud service provider.

Method 2: Configure Multiple IP Outlets and Policy Routing (Most Flexible)

If your VPS supports configuring multiple public IPs on a single network interface card (e.g., purchasing multiple Elastic IPs and binding them to the same VPS), you can achieve more granular control: allow the SSH service to use IP A, and the web crawler to use IP B.

This requires using Linux policy routing. Below are simplified steps for configuring and using it on a Linux VPS:

1. Bind multiple IPs to the network interface card: Assume the primary IP of the main network interface card `eth0` is `192.0.2.10`, and the cloud console has already bound another Elastic IP `203.0.113.20` to this instance.

# Add a secondary IP address to the eth0 network interface within the system.

sudo ip addr add 203.0.113.20/24 dev eth0

# Make the configuration take effect after a reboot (for Ubuntu/Debian, edit /etc/netplan/ or /etc/network/interfaces).

2. Create a new routing table: Edit `/etc/iproute2/rt_tables`, add a new table, for example, number `200`, named `table_vip`.

# Add a line to the file

200 table_vip

3. Configure routing rules for the new IP:

# Add a default gateway to the new routing table (assuming the gateway is 192.0.2.1)

sudo ip route add default via 192.0.2.1 dev eth0 table table_vip

# Add a rule: query the table_vip routing table for traffic from the secondary IP 203.0.113.20

sudo ip rule add from 203.0.113.20 table table_vip

4. Make a specific application use a specified egress IP: This is crucial. You can use `iptables`'s `SNAT` or `MARK` features, or more simply specify the source IP at the application layer.

Specifying the source IP using curl:

curl --interface 203.0.113.20 http://example.com

Specifying the source IP using the Python requests library:

python

import requests

Method 1: Using a proxy (socks5 is more flexible)

proxies = {

'http': 'socks5://203.0.113.20:1080',

'https': 'socks5://203.0.113.20:1080'

}

Method 2: Binding to a local address (requires the IP to be configured on the system network card)

This requires lower-level socket operations, or using the `source_address` parameter of requests (limited support in some versions). This method allows you to dynamically select the exit IP for different processes without restarting the service.

Method 3: Redirecting Traffic via a Proxy Gateway (Most Convenient)

If you feel that manipulating the underlying network of your VPS is risky, or if your VPS provider doesn't support multiple IPs, then using a proxy gateway is the simplest method. Your VPS acts as the client, sending traffic that needs to "change IPs" to the proxy server, which then uses its own IP to access the target.

The core is deploying or using a proxy service:

Set up the proxy on another VPS (the proxy server): For example, use `Squid` to set up an HTTP proxy, or use `Dante` to set up a SOCKS5 proxy.

A minimal Squid installation and basic configuration example:

sudo apt update && sudo apt install squid -y

sudo cp /etc/squid/squid.conf /etc/squid/squid.conf.backup

Edit the configuration file to allow access from your source VPS IP (e.g., 192.0.2.10).

Add the following to the configuration file: `acl client src 192.0.2.10`

Then: `http_access allow client`

sudo systemctl restart squid

The proxy server listens on port 3128 by default. Configure your applications to use a proxy on your primary VPS. This is a temporary global setting (effective for all commands that support the `HTTP_PROXY` environment variable):

`export http_proxy=http://proxy_server_IP:3128`

`export https_proxy=http://proxy_server_IP:3128`

# Then commands like curl and wget will run through this proxy.

`curl http://ifconfig.me` # This should return the proxy server's IP address.

Application-specific settings: Such as the Python `requests` library mentioned above, the `curl --proxy` parameter, etc.

Automatic switching script: You can prepare a script to quickly switch environment variables or switch between different proxy server configurations.

#!/bin/bash

# switch_proxy.sh

PROXY_LIST=("http://proxy1-ip:3128" "http://proxy2-ip:3128" "http://proxy3-ip:3128")

# Randomly select a proxy

SELECTED_PROXY=${PROXY_LIST[$RANDOM % ${#PROXY_LIST[@]}]}

export http_proxy=$SELECTED_PROXY

export https_proxy=$SELECTED_PROXY

echo "Proxy switched to: $SELECTED_PROXY"

Selection Suggestions and Precautions

For a complete and permanent change of identity: Choose Method 1 (Change Elastic IP). Suitable for scenarios where the IP is blocked by the target website and a "start over" is required.

For using different IPs for different tasks and requiring long-term stable use: Choose Method 2 (Multi-IP Policy Routing). Suitable for complex businesses requiring IP isolation, such as multi-account operation and data collection.

For those needing temporary, rapid, and frequent IP switching, or with limited technical capabilities: Choose Method 3 (Proxy Gateway). Combined with multiple proxy servers, it offers the fastest switching speed and has no intrusion into the main VPS network configuration.

Important Security and Compliance Tips:

1. Comply with the service provider's terms: Frequent IP changes or the use of proxies may violate the VPS service provider's "fair use policy."

2. Clarify the legality of the purpose: Ensure that the purpose of changing the IP is for legal and compliant uses, such as testing, privacy protection, or circumventing unreasonable regional blocking.

3. Proxy server security: If using a third-party proxy, pay close attention to data security and avoid transmitting sensitive information.

4. Prevent connection loss: Before performing any operation to change the main IP, ensure there is a backup connection method (such as VNC login from the cloud console).

In short, VPS "instant IP switching" is not magic, but a strategy based on the combination of existing network functions. Understand your core needs—whether it's changing your identity, splitting your network channels, or adding a jump server—and then choose the corresponding technical path; this will give you more control over your network environment.