PPPoE very slow with Sophos XG Firewall

Question

Hello, 
 i am using PPPoE on WAN, with a FritzBox as DSL-modem. The VDSL speed is 100 MBit/s. But after PPPoE login i have only 2,4 Mbps download speed. The Problem is not the VDSL-connection in itself. The CPU and RAM workload is okay. I can give no account of it. What can i do to increase the connection speed?

Uli RompelRompel · Answer

i have found out the cause: 
it was the "System Services " -> "DoS & Spoof Protection" -> "DoS Settings" -> Set all "Apply Flag"s 
Unset the Apply Flags causes speed up to full VDSL speed. 
Can anyone reproduce the Problem? 
Is it normal, that DoS causes such a high speed loss?

jeffmcfarlane · Answer

Spot on.. I was getting 256kbps downloading ISO files and your solution fixed the problem.. 
 Thanks