VPP Bond Subinterface Reconfiguration Causes Bond Connectivity Loss

Hello,

I found another issue related to VPP bonding and VLAN subinterfaces.

Reconfiguring a single subinterface on a bonded VPP interface causes all subinterfaces on the bond to go down, resulting in loss of connectivity across the entire bonded interface.

This makes the solution unstable in my environments.

    vpp {
        bonding vppbond0 {
            hash-policy layer3+4
            member {
                interface eth6
                interface eth7
                interface eth8
                interface eth9
            }
            mode 802.3ad
            mtu 1500
            vif 38 {
                address 198.51.100.2/30
                address 2001:db8:100::2/126
                mtu 1500
            }
            vif 30 {
                address 203.0.113.2/24
                mtu 1500
            }
        }
    }
}

Initial state:

vyos@r1# run show interfaces vpp

BondEthernet0      bond                       02:fe:d9:33:87:4d   9000  up
BondEthernet0.38  bond    198.51.100.2/30   00:00:00:00:00:00   1500  up
BondEthernet0.30  bond    203.0.113.2/24    00:00:00:00:00:00   1500  up

Removing a single IPv6 address from one VLAN subinterface:

delete interfaces vpp bonding vppbond0 vif 38 address 2001:db8:100::2/126

Immediately causes both VLAN subinterfaces to transition to DOWN state:

vyos@r1# run show interfaces vpp

BondEthernet0      bond                       02:fe:3e:39:fa:41   9000  up
BondEthernet0.38  bond    198.51.100.2/30   00:00:00:00:00:00   1500  down
BondEthernet0.30  bond    203.0.113.2/24    00:00:00:00:00:00   1500  down

Log:

May 21 18:01:34 r1 vpp[3037]: clib_c11_violation: s1 NULL
May 21 18:01:34 r1 vpp[3037]: clib_c11_violation: s2 NULL
May 21 18:01:34 r1 vpp[3037]: interface: hw_add_del_mac_address: vnet_hw_interface_add_del_mac_address: Secondary MAC Addresses not supported for >

Additional observations:

  • BondEthernet0 itself remains UP

  • All underlying DPDK interfaces remain operational

  • The issue appears to affect only VLAN subinterfaces on the VPP bonded interface

  • MAC addresses on subinterfaces are displayed as 00:00:00:00:00:00

  • VPP logs also report:
    Secondary MAC Addresses not supported for interface index 0

This behavior is reproducible and occurs during normal configuration changes such as adding/removing IP addresses from a single VIF.

Environment:

  • VyOS rolling / 2026.03

  • VPP dataplane

  • LACP bond with multiple VLAN subinterfaces

Please let me know if additional debugging information is required.

@PlaSec can you add a bug report on our bug/feature tracker? https://vyos.dev

Sure, I already added a bug report on the tracker.