change mss for PPPoE and IP Route users

RouterOS Beginner Basics
1

hello guys
good time

I calculated my network MTU size from ping 4.2.2.4 -l 1455 -f and I realized my network MTU is 1455

now, I have a question aboute change mss for my users
what ch-mss size should I set for PPPoE-client users and IP Route Users ?

IP Route : 1455-40 = 1415 is correct ?
PPPoE : 1455-40-6 = 1409 is correct ?

2

my network :

3

I should set ch-mss on interface (all ppp (my user ppooe)) or set ch-mss on interface connected to internet ??

4

MSS = MTU - TCP Header - IP Header …
What are those 6 Bytes on your second calculation ?

5

Some ping programs the length option specifies just the payload data, others the entire packet.

For Windows it is the payload, so from that if -l 1455 works and -l 1456 fails the MTU is 20 (IP header) + 8 (ICMP header) + 1455 (payload) = 1483, and correspoding MSS is 1483 (MTU) - 20 (IP header) - 20 (TCP header) = 1443.

6

PPPoE overhead = 8 Byte / its incorrect and not should calculated ?

7

thanks

8

It is 8 Bytes not 6… yes it should be calculated …