On 2018/03/30 1:49, Roopa Prabhu wrote: > On Thu, Mar 22, 2018 at 9:53 PM, Roopa Prabhu <ro...@cumulusnetworks.com> > wrote: >> On Thu, Mar 22, 2018 at 8:34 AM, Chas Williams <3ch...@gmail.com> wrote: >>> If the bridge is allowing multiple VLANs, some VLANs may have >>> different MTUs. Instead of choosing the minimum MTU for the >>> bridge interface, choose the maximum MTU of the bridge members. >>> With this the user only needs to set a larger MTU on the member >>> ports that are participating in the large MTU VLANS. >>> >>> Signed-off-by: Chas Williams <3ch...@gmail.com> >>> --- >> >> Acked-by: Roopa Prabhu <ro...@cumulusnetworks.com> >> >> This or an equivalent fix is necessary: as stated above, today the >> bridge mtu capped at min port mtu limits all >> vlan devices on top of the vlan filtering bridge to min port mtu. > > > On further thought, since this patch changes default behavior, it may > upset people. ie with this patch, a vlan device > on the bridge by default will now use the bridge max mtu and that > could cause unexpected drops in the bridge driver > if the xmit port had a lower mtu. This may surprise users. > > The other equivalent fix i was thinking about is to keep the default > behavior as is, and allow a max mtu to be > configured on the bridge. This will allow a sys admin to fix the > current mtu limitations if > deployments require it. > > we will submit an incremental patch to re-work this patch to restore > default behavior.
+1 This makes sense to me. -- Toshiaki Makita
