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

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

[Hannes Laimer]

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.

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};
 
-- 
2.47.3

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

[Stefan Hanreich]

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.

[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};
>  

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

[Hannes Laimer]

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};
>>  
> 
> 
> 
> 
>