Ask Web LJ: JavaScript Downloading Problem

[woodwardiocom]

So, at work we have an extranet site, which has several pages which include JavaScript files for assorted functionality. We recently started having problems where, internally, all was hunky-dory, but for people coming through the firewall, the JS files are getting truncated, thus breaking the site. Anyone seen this sort of behavior before? (We are not loading the JS files asynchronously; we're using perfectly ordinary <script></script> blocks.)

Comments

[drwex]

Did something change in the internal configuration or in the IP mapping, name service, or NATing?

My first guess is that it's a communications error that may be based on finding the right pieces. Truncation (rather than total failure) is a little weird though. Does it always happen at the same place in the file? If so, that may be a buffer-size issue. Does it happen at random places in the file? If so, look for connection timeout issues - maybe the firewall is dropping the connection when it shouldn't?

Are you able to stand up a test server on which you can make plausible changes, like removing one file known to get truncated and replacing it with a sample stub file (e.g. something very small)? Do you have a remote host on which you can log in to test how external users see thing?

I'm sort of flailing around here, sorry. Hope some of this is helpful.

[caulay.livejournal.com]

I once saw problems with firewall setting that caused any file larger than certain size to be truncated. You might want to check the size of the files on the server vs. the size when received via extranet.

Is this happening with *all* .js files or only some? This can be tested with a small dummy file that is only a comment and Firebug.

Also just make sure the firewall is set to allow .js files through, sometimes that's a problem.