Upgraded home MTIK to faster HW and got problems - many popular sites lagging a lot. This post helped to understand that the reason was MTU=1458 on the main bridge due to disabled but not deleted EoIP to summer house where EoIP MTU was not forced to any particular value, and become 1458 by default. Practical test shows that anything below 1500 is too low for internet to work properly.
I believe by default MTU shall stay 1500 as current logic to decrease it to 1458 creates problems and time waste for the users as it requires investigations why the internet is half functioning - many pages do not load without pressing refresh several times, etc. - the only practical solution is to make EoIP MTU to 1500 to get router back to working state.
In latest RouterOS version bridge MTU went instantly up from 1458 to 1500 after MTU of EoIP was changed to 1500.
MTIK needs to correct the default MTU for EoIP to be 1500 if not entered, NOT 1458. EoIP will need to send 2 frames if larger than 1458 frame enters tunnel and frameSize+EoIP overhead is above physical MTU max. between EoIP endpoints. Until default is not changed, every time after creating EoIP tunnel it is obligatory to correct wrong default and force 1500 for EoIP MTU - otherwise 1458 will be applied to main bridge and that breaks internet stability as too many popular sites refuse to fragment packets with MTU below 1500.
I believe by default MTU shall stay 1500 as current logic to decrease it to 1458 creates problems and time waste for the users as it requires investigations why the internet is half functioning - many pages do not load without pressing refresh several times, etc. - the only practical solution is to make EoIP MTU to 1500 to get router back to working state.
In latest RouterOS version bridge MTU went instantly up from 1458 to 1500 after MTU of EoIP was changed to 1500.
MTIK needs to correct the default MTU for EoIP to be 1500 if not entered, NOT 1458. EoIP will need to send 2 frames if larger than 1458 frame enters tunnel and frameSize+EoIP overhead is above physical MTU max. between EoIP endpoints. Until default is not changed, every time after creating EoIP tunnel it is obligatory to correct wrong default and force 1500 for EoIP MTU - otherwise 1458 will be applied to main bridge and that breaks internet stability as too many popular sites refuse to fragment packets with MTU below 1500.
Statistics: Posted by AlmantasK — Thu Jan 25, 2024 2:08 am