SDN not working after changing Proxmox host network, only recovers after toggling Firewall on the interface

Ronan311

New Member
Nov 8, 2025
4
0
1
Hi, i'm having an issue related to SDN in Proxmox. When I change the IP address of my Proxmox host, for example, from 172.16.228.11 to 172.16.228.10 and then restart the networking service, the entire SDN setup stops working. SDN interfaces attached to VMs no longer function, they cannot reach the gateway, and they also cannot communicate with other hosts in the same subnet.

However, when I toggle the Firewall option (check or uncheck) on the interface, everything starts working again. Is this a bug, or am I doing something wrong?

My network config:
Code:
auto lo
iface lo inet loopback

iface eno8303 inet manual

auto vmbr0
iface vmbr0 inet static
        address 10.17.69.51/24
        bridge-ports eno8303
        bridge-stp off
        bridge-fd 0

iface eno8403 inet manual

auto eno12399np0
iface eno12399np0 inet manual
        ovs_mtu 9000

auto eno12409np1
iface eno12409np1 inet manual
        ovs_mtu 9000

auto ens5f0np0
iface ens5f0np0 inet manual
        ovs_mtu 9000

auto ens5f1np1
iface ens5f1np1 inet manual
        ovs_mtu 9000

# Proxmox OVS Network Configuration
auto vmbr1
iface vmbr1 inet manual
    ovs_type OVSBridge
    ovs_ports bond0
    ovs_mtu 9000

# LACP
auto bond0
iface bond0 inet manual
    ovs_type OVSBond
    ovs_bridge vmbr1
    ovs_bonds ens5f0np0 ens5f1np1 eno12399np0 eno12409np1
    ovs_options bond_mode=balance-tcp lacp=active other_config:lacp-time=fast
    ovs_mtu 9000

# Proxmox Host
# Vlan ID 228 for Proxmox Host
auto vlan228
iface vlan228 inet static
    address 172.16.228.11/24   
    gateway 172.16.228.254
    ovs_type OVSIntPort
    ovs_bridge vmbr1
    ovs_options tag=228
    ovs_mtu 9000

1763112199732.png

1763112228700.png