Missing MRU in dial PPPoe Interfaces

There is currently an issue related to the MRU of the PPPoE interface.

Some service providers use heterogeneous configuration, causing the situation when setting MTU to 1492, only some website services can be accessed (google, facebook), and many website do not access.

The way to fix the problem is to add the MRU option in the PPPoE interface.

I can bypass with options “TCP MSS Clamping for PPPoE” but if can edit MRU parameter, I can confirm that there is no need to edit TCP MSS.

Here is the example I am facing, if I rotate pppoe without fixing the default MTU and MRU is 1492.

Can access facebook and google site but another site can’t access.

And if I changed MTU 1492 and MRU 1480, I access all.

Hi @cuongdt1994 Thank you for sharing your feature request! Your insight into the issue you’re facing with heterogeneous configuration and MTU settings is highly valuable, and we appreciate your efforts in finding a solution. Your feedback helps us enhance VyOS to cater to diverse networking environments and user needs. :pray:


What is MRU? I only head mtu and mss. MRU was the first time I heard it till now.
How about set MTU & MSS as shown below

#VyOS 1.3.x Version
set interfaces pppoe pppoe0 mtu '1492'
set firewall options interface pppoe0 adjust-mss '1452'

These vlues works well for me.

1 Like

MRU - Maximum Receiving Unit.


Added feature request ⚓ T5630 pppoe: allow to specify MRU in addition to already configurable MTU for the following release trains:

  • current (1.5)
  • sagitta (1.4)
  • equuleus (1.3)