A BNC (short for Bounced Network Connection) is a piece of software that is used to relay traffic and connections in
computer network
A computer network is a collection of communicating computers and other devices, such as printers and smart phones. In order to communicate, the computers and devices must be connected by wired media like copper cables, optical fibers, or b ...
s, much like a
proxy. Using a BNC allows a user to hide the original source of the user's connection, providing
privacy
Privacy (, ) is the ability of an individual or group to seclude themselves or information about themselves, and thereby express themselves selectively.
The domain of privacy partially overlaps with security, which can include the concepts of a ...
as well as the ability to route traffic through a specific location. A BNC can also be used to hide the true target to which a user connects.
[Lederer, Christian (phrozen77). (December 22, 2009)]
"IRC bouncer comparison"
. IRC-Junkie. December 22, 2009.
IRC

One common usage is over
Internet Relay Chat
IRC (Internet Relay Chat) is a text-based chat system for instant messaging. IRC is designed for Many-to-many, group communication in discussion forums, called ''#Channels, channels'', but also allows one-on-one communication via instant mess ...
(IRC) via a BNC running on remote
server
Server may refer to:
Computing
*Server (computing), a computer program or a device that provides requested information for other programs or devices, called clients.
Role
* Waiting staff, those who work at a restaurant or a bar attending custome ...
s. In such an environment, where it is very easy to ascertain a user's
IP address
An Internet Protocol address (IP address) is a numerical label such as that is assigned to a device connected to a computer network that uses the Internet Protocol for communication. IP addresses serve two main functions: network interface i ...
a BNC may help to hide the original connection source, as well as providing the opportunity for "
vhosts" or "virtual hosts". The use of a vhost does not conceal the connection any better but merely adds a statement as the hostname.
Many BNCs remain connected to an IRC server in the event the client should disconnect from the Internet. Often state changes are tracked so that they may be relayed to the client upon reconnection. Some implementations opt to store all messages sent across the network that the client would have normally received and send them upon the client's reconnection; this is often considered to be much too resource dependent for commercial hosting services to provide. Other logging features and
bot
Bot or BOT may refer to:
Sciences
Computing and technology
* Chatbot, a computer program that converses in natural language
* Internet bot, a software application that runs automated tasks (scripts) over the Internet
**Spambot, an internet bot ...
like functions may be included with various implementations but are not standard.
Example
:User A logs onto IRC directly and appears as
[email protected]
:User A logs onto IRC indirectly through a BNC and appears as
[email protected]
Software
A list of bouncers.
* The Lounge acts both as an IRC client and an IRC bouncer.
*
Quassel IRC
Quassel IRC, or Quassel, is a graphical, distributed, cross-platform IRC client, introduced in 2008.["Changelog"](_blank)
. ...
, or Quassel, is a graphical, distributed, cross-platform IRC client, introduced in 2008.
* soju is a user-friendly IRC bouncer, written in
Go, with support for chat history playback and file uploads, in development since 2020.
*
ZNC (IRC) is a popular IRC bouncer, written in
C++
C++ (, pronounced "C plus plus" and sometimes abbreviated as CPP or CXX) is a high-level, general-purpose programming language created by Danish computer scientist Bjarne Stroustrup. First released in 1985 as an extension of the C programmin ...
, in development since July 2004.
Hosted services
Several companies offer hosted IRC bouncer services:
* IRCCloud is an IRC bouncer based on proprietary software, with its own web and mobile IRC clients. It is developed mainly for teams and can be bridged with
Slack (software)
Slack is a Cloud computing, cloud-based team communication platform developed by Slack Technologies, which has been owned by Salesforce since 2020. Slack uses a freemium, freemium model. Slack is primarily offered as a business-to-business serv ...
.
* IRC Today is a commercial IRC bouncer based on the open source software soju. It features an intuitive web configuration interface and enables file upload directly from the IRC client.
* chat.sr.ht is another commercial IRC bouncer based on soju. It is part of a minimalistic software suite targeted at developers.
FTP
BNCs are also often used for
File Transfer Protocol
The File Transfer Protocol (FTP) is a standard communication protocol used for the transfer of computer files from a server to a client on a computer network. FTP is built on a client–server model architecture using separate control and d ...
(FTP), again to hide the
user
Ancient Egyptian roles
* User (ancient Egyptian official), an ancient Egyptian nomarch (governor) of the Eighth Dynasty
* Useramen, an ancient Egyptian vizier also called "User"
Other uses
* User (computing), a person (or software) using an ...
and
server
Server may refer to:
Computing
*Server (computing), a computer program or a device that provides requested information for other programs or devices, called clients.
Role
* Waiting staff, those who work at a restaurant or a bar attending custome ...
from each other and to route traffic through a specific location. FTP bouncers can be divided into two different categories, entry and traffic.
An entry bouncer acts as a
gateway to the server, but it does not hide the existence of the actual server. Entry bouncers, like
cubnc, can be used in a multiserver setup for easy access to each server and
load balancing. This removes the need to select which FTP server to log into, when trying to access the
server farm
A server farm or server cluster is a collection of Server (computing), computer servers, usually maintained by an organization to supply server functionality far beyond the capability of a single machine. They often consist of thousands of compu ...
.
Traffic bouncers relay traffic through the host they are installed on and present themselves as if they were the FTP server, thus hiding the real location of the server completely. Multiple traffic bouncers can be installed parallel in order to balance traffic load across different links. Most elaborate bouncers can even bounce secure
SSL/TLS
Transport Layer Security (TLS) is a cryptographic protocol designed to provide communications security over a computer network, such as the Internet. The protocol is widely used in applications such as email, instant messaging, and voice over IP, b ...
connections.
See also
*
Proxy
*
Open proxy
An open proxy is a type of proxy server that is accessible by any Internet user.
Generally, a proxy server only allows users within a network group (i.e. a closed proxy) to store and forward Internet services such as Domain Name System, DNS or w ...
References
{{Reflist
Internet privacy software
Computer security software
IRC