Forum Discussion

Retired_Member

Sep 14, 2020

Solved

Orbi RBR20 v2.5.1.16 IPv6 PPPoE missing TCPMSS

Orbi RBR20 firmware v2.5.1.16 WAN PPPoE IPv4+IPv6 - VDSL Provider - LiveTIM - Sao Paulo - Brazil IPv4, IPv6 and IPv6-PD (LAN) are aquired as expected I have no throuble in IPv4 services, eve...

CrimpOn
Sep 14, 2020
Retired_Member wrote:
Question
As I discovered this issue days after my 90 days support finished, I'm unable to report this bug through an official channel. How could I persist this soluction?
What seems to have worked in this situation is to send a private message to one of the forum moderators by clicking on their screen name, such as Dustin_V (the moderators have a capital "N" after their name). Moderators seem to have a mechanism to communicate with Netgear engineers and support staff.

CrimpOn

Guru - Experienced User

Sep 16, 2020

Please forgive my ignorance. Does this situation affect every ISP connection type?

i.e. both PPPoE and DHCP?

Retired_Member

Sep 16, 2020

CrimpOn wrote:
Please forgive my ignorance. Does this situation affect every ISP connection type?
i.e. both PPPoE and DHCP?

Retired_Member
Sep 16, 2020
Once my ISP provides PPPoE only, I'm unable to try others
- Retired_Member
  Sep 16, 2020
  MTU 1492, default for PPPoE, MSS adjusted to 1432 (-60 bytes)
  
  MTU 1452, MSS adjusted to 1392 (-60 bytes)
  
  Without ip6tables rule, MSS always is 1440, despite MTU value
  - Retired_Member
    Sep 19, 2020
    Other workaround is put radvd to advertase the WAN MTU value as IPv6 MTU to LAN, in PPPoE case, 1492. In this way LAN clients already send the mss 1432 and the router does not need ip6tables rule.
    
    /tmp/radvd.conf
    AdvLinkMTU 1492;
    
    But, again, how to persist this?