What are planetlab proxies?

Guide to finding, testing and using anonymous proxies for web surfing.

What are planetlab proxies?
Planetlab proxies are machines that are part of the planetlab research facility, which is an effort at studying global computing and communication. These proxies are always hosted by an academic institute and the majority of them are located in the USA so that most of their names end in .edu.

They are everything one could want from an anonymous proxy: they have a static IP, they are very fast, non-filtering and keep the connection alive, which means that the next request will be handled through the same proxy instead of a different proxy. As the saying goes 'If it's too good to be true, then it's probably not true.' So it is the same with planetlab proxies.

The main guide says planetlab proxies should be removed so you might not have any obvious planetlab proxies in your list. Some, however, are harder to detect and that is where this separate guide comes in.

What happens when I use a planetlab proxy?

Initially, nothing. It would appear as if you have found a very good and working proxy. However, after a short time a message will pop up on your screen which is something like this:

You are trying to use a node of the codeen network. Your IP is not recognized as being part of the planetlab consortium of IPs.

From that moment the proxy will stop working and you have no other option but to remove it from ProxyHunter - which by itself can be annoying if you have many proxies in your list, to find the one rogue proxy.

How do I detect planetlab proxies in Charon?

Planetlab proxies give themselves away in Charon when you are testing for new proxies. Here are the criteria:

- If DNS lookup is successful, their name usually has planetlab, planet or pl or something similar in their name. Additionally, their name ends in .edu.

- A planetlab proxy is always a gateway proxy, meaning that it will forward your requests to another proxy. In Charon the IP of this other proxy will show up under the gateway column. Usually a gateway proxy will forward requests to a proxy in the same cluster of IPs. For planetlab proxies this is not the case. For example, a usual gateway proxy configuration is 168.143.113.16 forwarding to 168.143.113.30. An example of a planetlab proxy configuration is 169.229.50.10 forwarding to something like 129.237.123.250. Additionally if you were to check the same planetlab proxy a few times, it might forward your requests to three seemingly random gateways.

- Planetlab proxies always use two ports: 3127 and 3128. Therefore, if you find a proxy in Charon which has both these ports open, you can bet that it is a planetlab proxy (even if the DNS lookup fails).

[The information taked from Proxy Guide: Planetlab proxies. ]