We have fooled around a lot with 1500 PPPoE MTU sizes and recently have a small issue with the latest tcp mss automatic changes that have been implemented in the latest releases after 6.39.2
Just by change the “change TCP mss” setting to “On” in the PPP server profile and checking the MTU sizes from website “https://www.speedguide.net/analyzer.php” we get the following:
MTU = 1494
MTU is somewhat optimized for broadband. If you are not on a PPPoE DSL connection that limits packet size, consider increasing your MTU to 1500 for optimal throughput.
MSS = 1454
Maximum useful data in each packet = 1454, which equals MSS.
Changing it to “Off” and refreshing the website we get:
MTU = 1500
MTU is fully optimized for broadband.
MSS = 1460
Maximum useful data in each packet = 1460, which equals MSS.
Any ideas why this happens? Ideally we should get the sames results with both settings since we have proper MTU sizes allowed and passed through the network.
Thanks