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jsgibbs1's avatar
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Feb 19, 2016

Troubleshoot LTM file upload

I need assistance troubleshooting an LTM file upload problem:


A web server allows browser based file uploads. However, when I move the server behind the LTM, the files are not passed. I don't see anything in the logs. I'm not running ASM or anything else that should be blocking/rejecting/stripping the files. I've never had an issue like this, so I'm not really sure where to begin. Appreciate any ideas.


  1. LTM v.11.3.x
  2. Standard Virtual Server using SSL termination (tried as Performance Layer 4 as well, no change)
  3. No iRules in place
  4. Test file is an blank .txt

3 Replies

  • Fyi, This turned out to be an issue on the customer's server.


  • "I don't see anything in the logs" means on the bigIP or on the webserver? If you see HTTP requests on the webserver, but the file upload does not finish, try deactivating nagle algorithm in the tcp profile if it is enabled. Had a similar issue a while ago. It turned out that nagle algorithm being activated in the tcp profile was the problem. The last portion of the file upload did never finish, because TCP was waiting for the last gap to be filled.
  • How big is your test file ? Try creating a :80 (no ssl termination) virtual for testing purposes, with the same pool members, and tcpdump the stream to see what's going on. Try removing the HTTP profile from the virtual if you have one, to eliminate that. Check /var/log/ltm as you're testing.