Re: [PATCH pve-network] sdn: zones: look the underlay interface up correctly

[Hannes Laimer <h.laimer@proxmox.com>]

On 2026-09-09 10:13, Stefan Hanreich wrote:
> On 9/9/26 9:53 AM, Hannes Laimer wrote:
>> The interfaces reader returns the table under a key, and the vxlan and
>> evpn zones looked their underlay interface up at the top level of the
>> reader's result, so the MTU they derive from it never applied and every
>> vnet bridge of theirs got the default or the zone's own MTU.
> 
> Ironically we independently discovered this yesterday [1], but we're a
> bit afraid of breaking setups that implicitly rely on that behavior.

:P

and agree, `ip link` would be the better source for this

> 
> [1] https://bugzilla.proxmox.com/show_bug.cgi?id=8018
> 
>> Signed-off-by: Hannes Laimer <h.laimer@proxmox.com>
>> ---
>> the alternative would be already passing `->{ifaces}`, but we'd lose the
>> options like that. i think this is better.
>>
>>  src/PVE/Network/SDN/Zones/EvpnPlugin.pm  | 3 ++-
>>  src/PVE/Network/SDN/Zones/VxlanPlugin.pm | 3 ++-
>>  2 files changed, 4 insertions(+), 2 deletions(-)
>>
>> diff --git a/src/PVE/Network/SDN/Zones/EvpnPlugin.pm b/src/PVE/Network/SDN/Zones/EvpnPlugin.pm
>> index 0e79707..f89decf 100644
>> --- a/src/PVE/Network/SDN/Zones/EvpnPlugin.pm
>> +++ b/src/PVE/Network/SDN/Zones/EvpnPlugin.pm
>> @@ -214,7 +214,8 @@ sub generate_sdn_config {
>>  
>>      my $mtu = 1450;
>>      if ($iface) {
>> -        $mtu = $interfaces_config->{$iface}->{mtu} - 50 if $interfaces_config->{$iface}->{mtu};
>> +        $mtu = $interfaces_config->{ifaces}->{$iface}->{mtu} - 50
>> +            if $interfaces_config->{ifaces}->{$iface}->{mtu};
>>      }
>>      $mtu = $plugin_config->{mtu} if $plugin_config->{mtu};
>>  
>> diff --git a/src/PVE/Network/SDN/Zones/VxlanPlugin.pm b/src/PVE/Network/SDN/Zones/VxlanPlugin.pm
>> index a408261..b4e743e 100644
>> --- a/src/PVE/Network/SDN/Zones/VxlanPlugin.pm
>> +++ b/src/PVE/Network/SDN/Zones/VxlanPlugin.pm
>> @@ -119,7 +119,8 @@ sub generate_sdn_config {
>>  
>>      my $mtu = 1450;
>>      if ($iface) {
>> -        $mtu = $interfaces_config->{$iface}->{mtu} - 50 if $interfaces_config->{$iface}->{mtu};
>> +        $mtu = $interfaces_config->{ifaces}->{$iface}->{mtu} - 50
>> +            if $interfaces_config->{ifaces}->{$iface}->{mtu};
>>      }
>>      $mtu = $plugin_config->{mtu} if $plugin_config->{mtu};
>>  
> 
> 
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> 
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