MONET - A Multi-homed Overlay Network

The machine runs a modified web proxy that does automatic failover to a DSL line that we recently had installed in lab, and to the lab's new 100 megabit connection from Cogent. When LCS is disconnected from MIT, or MIT from the rest of the network, it sends requests through the backup link. By using it, you get better browsing, and you help us conduct our research. Using the proxy provides three benefits:

How to use it

For normal access in Netscape/ie, set your proxy autoconfiguration file to use
For the ad blocking version, use
In other browsers, for the normal version, set your HTTP proxy to port 3128
or if there's no extra port specification.

For the ad blocking version, use: port 3129
or if there's no extra port specification.
Firebird / Mozilla users - note that the autoconfiguration support in some versions of firebird and mozilla is broken. When in doubt with these browsers, use manual configuration.

The autoconfiguration file makes your browser use the proxy only when browsing from inside LCS, and doesn't use the proxy for accessing MIT sites, or sites from which you need to have an MIT IP address (various library services, etc). If you manually configure your browser, make sure you only use it that way when browsing from LCS.

Mailing list

There'a a mailing list for users of the proxy. Go to the mailman page for the proxy list for more information.

Am I using the proxy?

It should say below. If not, view this page to determine if you're using the proxy.

How does this help me, the user?

If LCS's connection to MIT dies (we had 7 hours of said failures during March and April; this is not too rare), or MIT's connection to the rest of the world dies (often), you can still browse the web through the DSL line. It's also possible that some sites will load faster, through caching and if the DSL link is a lot closer to the website. Some may load a bit slower when using the proxy. Most will be the same, as most requests continue to go via MIT's primary network connection.

How does this help the research?

Data! I'm logging the requests that the machine makes to get an idea of how well this kind of system works in practice. And it's fun to actually be able to pound on it.

Clients are anonymized, and the URL is truncated at the CGI data markers, and the logfiles are private. We cannot associate requests with a particular user, and will never attempt to do so.

I always wished I had a proxy that ...

If you have suggestions for how we can improve the proxy, please let us know. Even if they're not directly related to the reliability research, we'd like to be able to offer good features as an incentive for people to use the proxy. Send mail!

Send a note to Dave Andersen - dga (at) - if you have questions or suggestions.


Opera 7 or Mozilla for Linux starts behaving weirdly...
The proxy autoconfiguration script for Opera 7 and for mozilla seems to be somewhat broken. Specify the HTTP proxy manually instead.
Can I use the proxy to access MIT resources from home?
MIT has site licenses for some things like and Using SSH tunnels, you can use the proxy to access them from home:
   ssh  <your_lcs_machine>
and then configure your local web browser to use localhost:3128 as the proxy. It's kind of a pain, and will slow down your browsing a bit (since it will tunnel everything in and out of MIT), but it beats coming in to work just to grab an article. You probably want to unset the proxy when you're done.


M. I. T. Laboratory for Computer Science · 200 Technology Square · Cambridge, MA 02139 · USA