Forward proxy vs. reverse proxy

I'm not familiar with the field, recently in the construction station, encountered this problem, make a record. Welcome to Criticize

(1) Forward proxy

I'm too lazy to draw my own notes.

The simple point to the proxy is that when user a accesses server B, it connects to Proxy server Z and accesses B through Z.

(The goagent used when turning over the wall is actually the forward agent.) When we visit some websites that are not allowed to visit, we use Goagent as a proxy, bypassing the "wall". ）

(2) Reverse proxy

Reverse proxy, that is, when user a visited the site, access to the reverse proxy server z, but the content of Z is secretly moved from Server B.

(3) What is the difference?

The above two pictures of the bad, see will be lost, I just to explain the convenience. The most fundamental difference between a forward proxy and a reverse proxy is:

1, using the forward proxy: User A and the forward proxy server is Z is a gang, the existence of the forward proxy is for user a service

2, when using reverse proxy: Server B and reverse proxy server z is a gang, the existence of reverse proxy is aware of Server B service

(4) Functional differences

The 3rd above has explained the essential difference between the forward proxy and the reverse proxy, and the following functional differences are based on the 3rd above.

The forward proxy is used for:

1. User A needs to bypass some obstacles to access server B

That is, there is no road between A and B, such as routing failure or "wall", proxy server is equivalent to help A to open a new road, so that a can reach B smoothly.

2, User A needs to speed up to B

Online game accelerator is the principle. Because a to go to B can have a lot of nodes (similar to the toll station, to wait for a long time), but if the existence of B,

You can reduce the number of toll stations on the way (you can save time).

3. Caching effects

Because there may be a lot of users under the proxy server, for some already have access to the content, the proxy server can be cached, in the future, when someone needs to access, there is no need to visit Server B

4. User Internet Behavior Control

If there is only one channel between User A and the Internet, and there is a forward proxy server z between the channels, then it means that all of the internet behavior of a (data sending and receiving) must pass Z,

That means you can limit the user's surfing behavior through Z.

5. Anonymous Access

When user A accesses server B through the forward proxy Z, B does not find the existence of a if it has not been agreed by Z, that is, Z helps to achieve anonymous access.

The reverse proxy is used to:

1, protect Server B.

The reason is that the reverse proxy server z and Server B are a bunch, somewhat similar to the feeling of customer service. You asked the customer service to ask a question, the customer service will find their company's internal people to find the answer, and then reply to you.

And who was she looking for? I'm not going to tell you. So sometimes you think China Mobile's stuff is too junk to chop off their technicians. No way! Because the customer service to help them withstand.

2. Buffering and load Balancing

The buffer is not said, with the same as the proxy, is to put some things to save, not every time to find the original Server B, improve efficiency.

Load balance, the simple is to say through Proxy server z, the request from the user balanced allocation to different servers B1, B2, B3 ...

This is a relatively large subject, you need to find out for yourself

(4) Content distribution CDN

Generally speaking, CDN is said to be the extension of the reverse proxy, through the internet above the distribution of multiple nodes, to reduce the time required for user access, you need to check the data it.

Interested to see this article, more than my notes more detailed, the picture of this article also from this article

"Graphic forward proxy, reverse proxy, transparent proxy"

Forward proxy vs. reverse proxy