Forward Proxy And Reverse Proxy Explained


The Difference Between Proxy and Reverse Proxy | strongDM

The Difference Between Proxy and Reverse Proxy | strongDM

Many businesses use proxy servers to route and secure traffic between networks. There’s often confusion, however, on how this differs from a reverse proxy. In this post, we’ll dissect the two concepts and explain how administrators can use a reverse proxy for easy access management is a proxy server? A proxy server, sometimes referred to as a forward proxy, is a server that routes traffic between client(s) and another system, usually external to the network. By doing so, it can regulate traffic according to preset policies, convert and mask client IP addresses, enforce security protocols, and block unknown stems with shared networks, such as business organizations or data centers, often use proxy servers. Proxy servers expose a single interface with which clients interact without having to enforce all of the policies and route management logic within the clients is a reverse proxy? A reverse proxy is a type of proxy server. Unlike a traditional proxy server, which is used to protect clients, a reverse proxy is used to protect servers. A reverse proxy is a server that accepts a request from a client, forwards the request to another one of many other servers, and returns the results from the server that actually processed the request to the client as if the proxy server had processed the request itself. The client only communicates directly with the reverse proxy server and it does not know that some other server actually processed its request. A traditional forward proxy server allows multiple clients to route traffic to an external network. For instance, a business may have a proxy that routes and filters employee traffic to the public Internet. A reverse proxy, on the other hand, routes traffic on behalf of multiple servers. A reverse proxy effectively serves as a gateway between clients, users, and application servers. It handles all the access policy management and traffic routing, and it protects the identity of the server that actually processes the verse proxy configurationBy routing client traffic through a reverse proxy, admins can simplify security administration. They can configure backend servers to only accept traffic directly from the proxy and then configure the granular access control configurations on the proxy example, admins can configure the reverse proxy’s firewall to whitelist or blacklist specific IP addresses. All existing servers behind the proxy will be protected accordingly, and whenever admins add a new backend server to the network that is configured to only accept requests from the proxy server, the new backend server is protected according to the proxy configuration. Using a reverse proxy can also allow administrators to easily swap backend servers in and out without disrupting traffic. Because clients interact directly with the proxy, they only need to know its host name and don’t need to worry about changes to the backend network topology. In addition to simplifying client configuration, an admin can configure a reverse proxy to load-balance traffic so that requests can be more evenly distributed to the backend servers and improve overall case: onboarding and off-boardingWhen onboarding a new user to a network, administrators must configure access control and firewalls to ensure the user can access the appropriate resources. Traditionally, an admin has to configure each server for which users need access. In a large organization with many servers, this can be a time-consuming and error-prone process. However, with a reverse proxy, administrators can configure the access rights directly on the proxy server and have the user route all traffic through it. As such, the backend servers only need to trust and communicate with the proxy directly. This greatly simplifies the configuration process and helps ensure access is granted and revoked correctly by doing so through a single tting up a reverse proxy for access managementWhile a reverse proxy can greatly simplify the process of managing access to a network, setting it up and configuring it properly can get complicated. It requires provisioning the host with appropriate specifications, configuring the operating system and firewall, deciding on which proxy software to use (such as NGINX or HAProxy), enumerating and configuring the downstream servers in the proxy configuration files, setting up audit logging, and configuring the firewalls in all the downstream servers. An administrator will need to optimize the proxy software to adjust for performance and availability requirements. For example, when a downstream server fails, the admin should configure the proxy server to quickly reroute traffic to avoid scale, the out-of-the-box configurations are rarely sufficient, so testing becomes important. Whenever the configurations change, you’ll need a way to run sufficient load against a representative test environment and closely monitor the impact on both performance and availability to verify that configurations will meet the needs of the production ing a reverse proxy by hand vs. buying softwareGiven all the steps involved in implementing, testing, and optimizing a reverse proxy, you may choose to buy software that can provide this functionality without all the custom work. Access management software can provide all of this functionality while also managing the ongoing maintenance and user management. In addition to providing standard reverse proxy capabilities, access management software affords a number of unique benefits:‍1) Flexibility with user access. By abstracting away the complexity of firewalls and access control, access management software can provide higher-level concepts like user groups. This functionality makes it easy for admins to assign and remove users from various predefined groups and allows the software to automatically implement the access policies. 2) Designed to boost reliability. In distributed systems, servers can fail and network interruptions may occur. Access management software easily detects failed servers and reroutes traffic to working ones to avoid any noticeable downtime for users. 3) Load balancing capabilities. Single servers may struggle when hit with a large amount of traffic, which degrades performance and increases request latency. Access management software can help to manage traffic and balance the load across all servers, making sure it’s evenly naging access with strongDMThe strongDM control plane is a proxy-based solution that simplifies authentication and authorization for admins. It routes all database and server connections through its protocol-aware proxy over a TLS 1. 2 secure TCP connection, and it handles load balancing and automatic failover to provide high availability. The proxy validates user sessions and permissions and then intelligently routes the session to the target database or server through the most efficient path, logging all traffic along the rongDM extends the single sign-on capabilities of your identity provider, allowing you to authenticate users to any server or database. From the Admin UI, you can view connected resources and manage role-based access control for your users. See for yourself with a free, 14-day trial. ‍ this post? Then get all that SDM goodness, right in your you! Your submission has been received! Oops! Something went wrong while submitting the form.
Why is the Nginx webserver called a

Why is the Nginx webserver called a “reverse proxy”?

Why is the Nginx webserver called a “reverse proxy”? I know any “proxy” to be a “medium” and this touches a more basic question of “how can a medium be forward or reverse”.
A typical “forward” proxy (commonly just called “proxy”) is used to allow internal clients to reach out to external sites.
For example, a corporation may have desktop users who want to reach the internet, but firewalls block them. The users can configure their browser to reach a proxy server, which will make the connection for them.
A “reverse” proxy allows external clients to reach in to internal sites.
For example, a corporation may run a dozen different web sites behind a firewall. A reverse proxy would be programmed so that incoming requests for “” will be forwarded to the real web server for that site. In this way the corporation only needs to expose one real web server.
There are many use cases for both forward and reverse proxies.
nginx is a web server, similar to apache and IIS. Like many web servers it can be configured to work in forward proxy mode or reverse proxy mode.
The phrase “nginx reverse proxy” means the nginx server configured as a reverse proxy.
answered Feb 15 ’19 at 2:52
Stephen HarrisStephen Harris36. 5k5 gold badges78 silver badges103 bronze badges
Why is the Nginx webserver called a “reverse proxy”?
“Reverse proxy” refers to a specific function that a specific Nginx instance can take on. Other Nginx instances can be ordinary web servers, or mail proxies or even load balancers (which often refers to “reverse proxy across multiple servers”).
I know any “proxy” to be a “medium”
A more accurate term is “intermediary”, as in “I’m accessing some resources on your behalf”. “Medium” as a noun can also refer to the transport mechanism over which you’re communicating.
and this touches a more basic question of “how can a medium be forward or reverse”.
The difference between forward and reverse proxies lies in the association, which basically asks the question: “Whose interests am I serving? ”
In a forward proxy, the association is with the clients, i. e. “I’m helping my select group of users access arbitrary servers”.
In a reverse proxy, the association is with the servers, i. “I’m helping my select group of servers manage all incoming requests from arbitrary clients”.
answered Feb 15 ’19 at 3:35
AdrianAdrian1, 8261 gold badge8 silver badges9 bronze badges
Reverse proxy - Wikipedia

Reverse proxy – Wikipedia

Example scenario: A client on the internet (cloud on the left) makes a request to a reverse proxy server (red oval in the middle). The proxy inspects the request, determines that it is valid and that it does not have the requested resource in its own cache. It then forwards the request to some internal web server (oval on the right). The internal server delivers the requested resource back to the proxy, which in turn delivers it to the client. The client on the internet is unaware of the internal network, and cannot tell whether it is communicating with a proxy or directly with a web server.
In computer networks, a reverse proxy is a type of proxy server that retrieves resources on behalf of a client from one or more servers. These resources are then returned to the client, appearing as if they originated from the reverse proxy server itself. [1] It is mainly used to balance load.
Large websites and content delivery networks use reverse proxies, together with other techniques, to balance the load between internal servers. Reverse proxies can keep a cache of static content, which further reduces the load on these internal servers and the internal network. It is also common for reverse proxies to add features such as compression or TLS encryption to the communication channel between the client and the reverse proxy. [2]
Reverse proxies are typically owned or managed by the web service, and they are accessed by clients from the public internet. In contrast, a forward proxy is typically managed by a client (or their company) who is restricted to a private, internal network, except that the client can ask the forward proxy to retrieve resources from the public internet on behalf of the client.
Reverse proxy servers are implemented in popular open-source web servers such as Apache, Nginx, and Caddy. This software can inspect HTTP headers, which, for example, allows it on a single IP address to relay requests to different internal servers based on the domain name of the HTTP request. Dedicated reverse proxy servers such as the open source software HAProxy and Squid are used by some of the biggest websites on the internet. Popular commercial providers of reverse proxy servers include Cloudflare and Imperva.
Reverse proxies can hide the existence and characteristics of origin servers.
Application firewall features can protect against common web-based attacks, like a denial-of-service attack (DoS) or distributed denial-of-service attacks (DDoS). Without a reverse proxy, removing malware or initiating takedowns, for example, can be difficult.
In the case of secure websites, a web server may not perform TLS encryption itself, but instead offload the task to a reverse proxy that may be equipped with TLS acceleration hardware. (See TLS termination proxy. )
A reverse proxy can distribute the load from incoming requests to several servers, with each server supporting its own application area. In the case of reverse proxying web servers, the reverse proxy may have to rewrite the URL in each incoming request in order to match the relevant internal location of the requested resource.
A reverse proxy can reduce load on its origin servers by caching static content and dynamic content, known as web acceleration. Proxy caches of this sort can often satisfy a considerable number of website requests, greatly reducing the load on the origin server(s).
A reverse proxy can optimize content by compressing it in order to speed up loading times.
In a technique named “spoon-feeding”, [3] a dynamically generated page can be produced all at once and served to the reverse proxy, which can then return it to the client a little bit at a time. The program that generates the page need not remain open, thus releasing server resources during the possibly extended time the client requires to complete the transfer.
Reverse proxies can operate wherever multiple web-servers must be accessible via a single public IP address. The web servers listen on different ports in the same machine, with the same local IP address or, possibly, on different machines with different local IP addresses. The reverse proxy analyzes each incoming request and delivers it to the right server within the local area network.
Reverse proxies can perform A/B testing and multivariate testing without placing JavaScript tags or code into pages.
A reverse proxy can add basic HTTP access authentication to a web server that does not have any authentication. [4]
A reverse proxy can track all IP addresses making requests through it and it can also read and modify any non-encrypted traffic. Thus it can log passwords or inject malware, and might do so if compromised or run by a malicious party.
When the transit traffic is encrypted and the reverse proxy needs to filter/cache/compress or otherwise modify or improve the traffic, the proxy first must decrypt and re-encrypt communications. This requires the proxy to possess the TLS certificate and its corresponding private key, extending the number of systems that can have access to non-encrypted data and making it a more valuable target for attackers.
The vast majority of external data breaches happen either when hackers succeed in abusing an existing reverse proxy that was intentionally deployed by an organisation, or when hackers succeed in converting an existing Internet-facing server into a reverse proxy server. Compromised or converted systems allow external attackers to specify where they want their attacks proxied to, enabling their access to internal networks and systems.
Applications that were developed for the internal use of a company are not typically hardened to public standards and are not necessarily designed to withstand all hacking attempts. When an organisation allows external access to such internal applications via a reverse proxy, they might unintentionally increase their own attack surface and invite hackers.
If a reverse proxy is not configured to filter attacks or it does not receive daily updates to keep its attack signature database up to date, a zero-day vulnerability can pass through unfiltered, enabling attackers to gain control of the system(s) that are behind the reverse proxy server.
Using the reverse proxy of a third party (e. g. Cloudflare, Imperva) places the entire triad of Confidentiality, Integrity and Availability in the hands of the third party who operates the proxy.
If a reverse proxy is fronting many different domains, its outage (e. by a misconfiguration or DDoS attack) could bring down all fronted domains. [5]
Reverse proxies can also become a single point of failure if there is no other alternative obvious way to access the back end server directly.
See also[edit]
Network address translation
^ “Forward and reverse proxies”. The Apache Software Foundation. Retrieved 26 August 2018.
^ “Proxy servers and tunneling”. MDN Web Docs. Retrieved 6 December 2020.
^ “squid-cache wiki entry on “SpoonFeeding””. Francesco Chemolli. Retrieved 9 February 2011.
^ “Possible to add basic HTTP access authentication via HAProxy? “.
^ “Cloudflare outage knocks out major sites and services, including Discord”. Retrieved 14 December 2020.

Frequently Asked Questions about forward proxy and reverse proxy explained

How does forward proxy work?

A forward proxy is what most people call ‘a proxy’. You send a connection request to it, and the forward proxy retrieves data from the internet. It usually lets clients on an otherwise firewall-restricted network to access the internet.

What is a forward proxy used for?

A forward proxy is the most common form of a proxy server and is generally used to pass requests from an isolated, private network to the Internet through a firewall. Using a forward proxy, requests from an isolated network, or intranet, can be rejected or allowed to pass through a firewall.

Why is a reverse proxy called reverse?

Why is the Nginx webserver called a “reverse proxy”? “Reverse proxy” refers to a specific function that a specific Nginx instance can take on. Other Nginx instances can be ordinary web servers, or mail proxies or even load balancers (which often refers to “reverse proxy across multiple servers”).Feb 15, 2019

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