Re: Travel router part 2

[Robert Swindells <rjs%fdy2.co.uk@localhost>]

D'Arcy Cain <darcy%NetBSD.org@localhost> wrote:
>On 2018-09-02 12:10 PM, Robert Swindells wrote:
>> 
>> D'Arcy Cain <darcy%NetBSD.org@localhost> wrote:
>>> On 2018-09-02 10:03 AM, Robert Swindells wrote:
>>>>> The idea is to use re0 as my DSL connection and later to use athn1 in
>>>>> the campgrounds as I travel.  Here is the relevant portion of my rc.conf.
>>>>
>>>> Maybe use wm0 as the external interface.
>>>
>>> What would that give me?
>> 
>> You trimmed the paragraph of my reply that described what it would give
>> you.
>
>Sorry, I thought that it was unrelated.  Are you saying that using wm0
>would allow me to set the MTU but re0 doesn't?

Yes.

>> If you don't have an MTU of 1500 on pppoe0 you will have to deal with
>> MSS-clamping for your internal networks.
>
># ifconfig pppoe0 mtu 1508
>ifconfig: SIOCSIFMTU: Invalid argument

You don't set the mtu for pppoe0, you set it for the underlying ethernet
device.