What is a backconnect proxy and how does it work

Proxeta residential and mobile proxies are backconnect proxies: the string always has the same host, while the IP the site sees comes from a pool. This article explains how such a gateway works, how the login controls rotation and sticky sessions, and how backconnect differs from a list of addresses and from a static ISP proxy.

What is a backconnect proxy

A backconnect proxy (also called a proxy gateway or a rotating proxy) is an intermediary server with one address to connect to and a pool of exit IPs behind it. A request travels like this:

your software → gateway: one host and port → exit IP from the pool → site

1. Your software connects to the gateway and sends the username and password.
2. The gateway reads the parameters from the login and picks an exit address: in the right country, region or city, with the right internet provider or mobile carrier.
3. The connection reaches the site from that address. The site sees the exit IP and never the gateway’s address.

The gateway host is the same for every customer and does not change; the exit addresses do. So test a proxy by its exit IP, with a service that returns your address, not by the host’s address.

How one host and port hand out many IPs

The gateway picks an exit address per connection, not per request. While a connection is open, every request inside it leaves from one address: for an https:// site this is an encrypted tunnel from your software to the site, and the gateway cannot switch exits in the middle of it. A new connection means a new choice of address.

So how your software opens connections decides when the IP changes:

• curl opens a new connection on every run;
• a browser opens several connections even for one page;
• an HTTP library with a connection pool (keep-alive) can send hundreds of requests over one connection.

The port only selects the protocol: 8080 for HTTP, 1080 for SOCKS5. Strings with the same settings differ only in the port, and they share the login and the rules for picking an address.

Rotation and sticky sessions: the login decides

The session mode is written into the login with the sid parameter. An illustrative example:

proxy.example.invalid:8080:login-country-us-filter-medium:password
proxy.example.invalid:8080:login-country-us-sid-k7m2q9x4ab-filter-medium:password

The first string rotates and the second is a sticky session; filter-medium at the end is the “Quality” pool filter, which the generator sets by default.

• No sid: rotation. Every new connection gets an IP from the pool afresh.
• With sid: a sticky session. While the string stays the same, the gateway keeps one exit IP for it for as long as possible, until the provider drops the connection. The session length cannot be set and is not guaranteed, so check the IP after reconnecting.
• A different sid: a different session. Each string in a batch gets its own sid, so 10 strings are 10 separate sessions, one per thread or profile.

You can check this with a loop: two requests with a rotating string and two each with two sticky session strings.

for login in login-country-us login-country-us-sid-k7m2q9x4ab login-country-us-sid-p3w8n1c5zd; do
  for i in 1 2; do
    printf '%s  ' "$login"
    curl -sS --max-time 30 -w '\n' \
      --proxy http://proxy.example.invalid:8080 \
      --proxy-user "$login:password" \
      https://api64.ipify.org
  done
done

With the rotating string, the address changes from request to request. Each sticky session string gets the same address in both answers, and the two strings each have their own. The loop was run on November 5, 2026 through a local test proxy, not through the Proxeta gateway; curl’s flags and errors are explained in curl with a proxy.

The other login parameters

Country, region, city, ISP or ZIP code, proxy type, IPv4 and the pool filter narrow down the addresses the gateway chooses from. A mobile string differs from a residential one only by the type-mobile parameter, and both types draw on one traffic balance. The full order of parameters and the allowed combinations are in proxy string format.

It is better not to build the login by hand. The generator in the “Generate proxies” section of your Dashboard fills in the location codes itself, while an unknown code, an extra parameter or a broken order can make the gateway refuse the sign-in or return an IP from the wrong location.

Backconnect, a list of addresses and an ISP proxy

Proxeta residential and mobile proxies work as a backconnect gateway. For ISP proxies, the order in the “My proxies” tab lists the IP itself, and region, city and session cannot be set; see ISP proxies.

When backconnect fits and when it does not

It fits:

• Independent requests to public pages from a chosen location, with rotation.
• Multi-step flows where the site needs to recognize you between requests, with a sticky session, one string per thread or profile. When to use which mode is covered in sticky session vs rotation.
• Working without a list of addresses. Changing the country or city means taking another login; the host and port stay the same.

It does not fit:

• The same address for days or weeks: take an ISP proxy.
• Sign-in by IP without a username and password: there is none, only username and password.
• UDP: the gateway does not carry it; see HTTP vs SOCKS5.

Rotation spreads requests across addresses but does not change the rules: to a site, they are the same requests from the same project. Follow each site’s terms and the Proxeta Acceptable Use Policy.