Edited (edits are in italics):
In my configuration I have an Apache 2.2 Http Server configured as a reverse proxy with mod_proky_jk, that exposes http service from an Apache Tomcat 6 application server. The two are different MS Windows 2008 R2 boxes.
My problem is that communication between a remote mobile device connected via GPRS or GSM sometimes fails.
I found this message and it seems to fit my situation.
Dumping TCP messages, I noticed that Apache requests packets with the DF bit set to "don't fragment". The Ethernet frame size is actually 1514 and MTU is 1500.
Is there a way to tell Apache to not use DF bit? Maybe binding the service to the machine IP instead of all interfaces?
The new quetion is:
If the problem is caused by PPPoE added bytes, setting a lower MTU on the two Windows boxes may correct this problem?
I noticed that some mobile device failed the communication, other didn't fail. I analyzed the differences between two of these devices and noticed in the WWAN settings in Tools > Data configuration the the non working one had "Enable automatic configuration" not checked. I checked it and warm rebooted and the connection succeded. I unchecked it and the connection still succeded. This device never failed again.
Maybe I caught the problem? What does this setting affect at the communication level?