The symptoms of this problem appeared with random students/teachers saying they were getting errors based on the size of the posts they were making into forums and glossaries so I raised it here.
However, after further investigation we have noticed that our Checkpoint firewall is dropping connections when students/teachers are posting for at least two reasons:
- TCP sequence out of order
- Injection attacks
We have initially changed the "drop" connection to "log" for #1 above hoping this would allow the submissions to go through, but when we got reports of more failures we looked further and found that posts were also being dropped because it looked like an "injection attack"
The posts in question were using core Moodle modules (Forums, Glossaries) so no 3rd party code at play here.
What is more frustrating is that some students are clearly succeeding in posting, so it is either intermittent or related to the content students are posting.
One student wrote to me:
I tried my posts several times and when they did not work, I logged out and then in again. Therefore, each time I tried I was faster at writing my reply. In the end, it probably took me perhaps a minute until I clicked to post it on the forum. I do know other students and teachers who have had the same issue.
We are trying to follow this up with Checkpoint as well, but as it stands we are incredibly frustrated because the goodwill our students/staff have extended is rapidly disappearing if they have difficulty completing work online.
Has anyone experienced this before or have any suggestions in terms of where I could go to try to resolve this from here?
Cheers in advance,