Editing radvd.conf?

[-AndyH-]

Hi

Is it possible to edit radvd.conf? For some reason, the default is to broadcast a MTU of 1480 even though I want an MTU of 1500.

interface br0
{
IgnoreIfMissing on;
AdvSendAdvert on;
MinRtrAdvInterval 3;
MaxRtrAdvInterval 10;
AdvHomeAgentFlag off;
AdvManagedFlag off;
AdvOtherConfigFlag on;
AdvLinkMTU 1480;
prefix 2a02:16c8:xxxx:xxxx::/64
{
AdvOnLink on;
AdvAutonomous on;
};

This is causing packets to fragment.

Thanks

 

[RMerlin]

Hi

Is it possible to edit radvd.conf? For some reason, the default is to broadcast a MTU of 1480 even though I want an MTU of 1500.

Not with stock firmware. The file is dynamically generated by the firmware before starting the radvd service.

Note that the MTU for 6to4, 6in4 and 6rd is already configurable on the IPv6 page of the router's webui.

 

[-AndyH-]

Not with stock firmware. The file is dynamically generated by the firmware before starting the radvd service.

Note that the MTU for 6to4, 6in4 and 6rd is already configurable on the IPv6 page of the router's webui.

Hi

Thanks - I thought so (was getting read only when trying to save the edited file so assumed it was already written to the nvram).

Not quite sure why the MTU is 1480 in 374_5047.

I'm using the native IPv6, so there is no option to manually set the MTU. I am trying to do some testing with the MTU set to 1492 to see if PMTUD works properly (checking TCPDump for ICMP6 Packet Too Big Messages).

Unrelated, but is there any way of checking the RP-PPPoE version (I assume this is what the firmware is using for PPPoE connections)?

Thanks

 

[RMerlin]

Hi

Thanks - I thought so (was getting read only when trying to save the edited file so assumed it was already written to the nvram).

Not quite sure why the MTU is 1480 in 374_5047.

I'm using the native IPv6, so there is no option to manually set the MTU. I am trying to do some testing with the MTU set to 1492 to see if PMTUD works properly (checking TCPDump for ICMP6 Packet Too Big Messages).

Unrelated, but is there any way of checking the RP-PPPoE version (I assume this is what the firmware is using for PPPoE connections)?

Thanks

No idea about native IPv6, I only have access to a tunnel, and I never really looked in details at the implementation.

Asuswrt uses RP-PPPoE 3.11.

 

[-AndyH-]

Thanks

Will make the suggestion to Asus HQ about being able to set the MTU for native IPv6 (or at least override the radvd settings).