> On 23 May 2020, at 7:54 am, Christopher Zimmermann <chr...@openbsd.org> wrote:
>
> On Tue, Apr 21, 2020 at 04:12:16PM -0700, Chris Cappuccio wrote:
>> Tom Smyth [tom.sm...@wirelessconnect.eu] wrote:
>>> Hi Chrisz,
>>>
>>> 4 bytes for the vlan header .. have you tried increasing the parent
>>> intetface mtu by 4bytes
>>>
>>
>> IFCAP_VLAN_MTU is a direct bypass for this. "hardmtu" on the parent interface
>> is perhaps more interesting as it will limit everything including these
>> encapsulations
>
> IFAP_VLAN_MTU will affect how the hardmtu is passed on to vlan child
> interfaces. The vlan interfaces won't care for the parent's "soft" mtu AFAICS:
That is correct.
> hardmtu = ifp0->if_hardmtu;
> if (!ISSET(ifp0->if_capabilities, IFCAP_VLAN_MTU))
> hardmtu -= EVL_ENCAPLEN;
>
> Linux uses a MTU of 1536 for Pegasus chips. We always default to a hardmtu of
> 1500. So the hardmtu can't be the cause for my interface not managing
> full-size vlan.
We should set the hardmtu of the Pegasus chips higher then. Does Linux include
the Ethernet header in that MTU there?
dlg
>
> Christopher
>
>
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