After applying the update on my servers, I got massive problems in the stability of my network connections. I was running bond in mode 6, which now seems not to work anymore.

auto bond0
iface bond0 inet static
    hwaddress ether 00:30:88:88:88:88

    address 192.168.111.5
    netmask 255.255.254.0
    network 192.168.111.0
    broadcast 192.168.112.255
    gateway 192.168.111.1
    dns-nameservers 127.0.0.1
    dns-search bar.local

    # Both network interfaces
    slaves eth0 eth1

    # (balance-alb) Adaptive load balancing
    bond_mode 6

    bond_miimon 100
    bond_updelay 200
    bond_downdelay 200

My kern.log got flushed with the following "Jun 20 12:33:57 foo kernel: [ 1043.270668] bonding: bond0: Error: found a client with no channel in the client's hash table", followed by up/down messages from time to time:

[...]
Jun 20 12:33:31 foo kernel: [ 1009.900122] bonding: bond0: Error: found a client with no channel in the client's hash table
Jun 20 12:33:31 foo kernel: [ 1009.900123] bonding: bond0: Error: found a client with no channel in the client's hash table
Jun 20 12:33:31 foo kernel: [ 1009.900125] bonding: bond0: Error: found a client with no channel in the client's hash table
Jun 20 12:33:31 foo kernel: [ 1010.774755] e1000e: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX/TX
Jun 20 12:33:31 foo kernel: [ 1010.862510] bonding: bond0: link status up for interface eth0, enabling it in 0 ms.
Jun 20 12:33:31 foo kernel: [ 1010.862514] bonding: bond0: link status definitely up for interface eth0.
Jun 20 12:33:31 foo kernel: [ 1010.862517] bonding: bond0: making interface eth0 the new active one.
Jun 20 12:33:31 foo kernel: [ 1010.863951] bonding: bond0: first active interface up!
Jun 20 12:33:31 foo kernel: [ 1010.900005] bonding: bond0: Error: found a client with no channel in the client's hash table
Jun 20 12:33:31 foo kernel: [ 1010.900007] bonding: bond0: Error: found a client with no channel in the client's hash table
Jun 20 12:33:31 foo kernel: [ 1010.900008] bonding: bond0: Error: found a client with no channel in the client's hash table
Jun 20 12:33:31 foo kernel: [ 1010.900010] bonding: bond0: Error: found a client with no channel in the client's hash table
[...]
Jun 20 12:34:53 foo kernel: [ 1050.282624] bonding: bond0: Error: found a client with no channel in the client's hash table
Jun 20 12:34:53 foo kernel: [ 1050.673490] e1000e: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX/TX
Jun 20 12:34:53 foo kernel: [ 1050.733759] bonding: bond0: link status up for interface eth0, enabling it in 0 ms.
Jun 20 12:34:53 foo kernel: [ 1050.733762] bonding: bond0: link status definitely up for interface eth0.
Jun 20 12:34:53 foo kernel: [ 1050.733765] bonding: bond0: making interface eth0 the new active one.
Jun 20 12:34:53 foo kernel: [ 1050.735167] bonding: bond0: first active interface up!
Jun 20 12:34:53 foo kernel: [ 1063.804210] e1000e: eth0 NIC Link is Down
Jun 20 12:34:53 foo kernel: [ 1063.833760] bonding: bond0: link status down for interface eth0, disabling it in 200 ms.
Jun 20 12:34:53 foo kernel: [ 1064.033767] bonding: bond0: link status definitely down for interface eth0, disabling it
Jun 20 12:34:53 foo kernel: [ 1064.034501] bonding: bond0: now running without any active interface !
Jun 20 12:34:53 foo kernel: [ 1064.362507] bonding: bond0: Error: found a client with no channel in the client's hash table
Jun 20 12:34:53 foo kernel: [ 1064.362510] bonding: bond0: Error: found a client with no channel in the client's hash table
Jun 20 12:34:53 foo kernel: [ 1064.362512] bonding: bond0: Error: found a client with no channel in the client's hash table
Jun 20 12:34:53 foo kernel: [ 1064.362514] bonding: bond0: Error: found a client with no channel in the client's hash table
[...]
Jun 20 12:33:31 foo kernel: [ 1010.900118] bonding: bond0: Error: found a client with no channel in the client's hash table
Jun 20 12:33:31 foo kernel: [ 1010.900120] bonding: bond0: Error: found a client with no channel in the client's hash table
Jun 20 12:33:31 foo kernel: [ 1017.245555] e1000e: eth1 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX/TX
Jun 20 12:33:31 foo kernel: [ 1017.272973] bonding: bond0: link status up for interface eth1, enabling it in 200 ms.
Jun 20 12:33:31 foo kernel: [ 1017.460008] bonding: bond0: link status definitely up for interface eth1.
Jun 20 12:33:56 foo kernel: [ 1042.481383] e1000e: eth1 NIC Link is Down
Jun 20 12:33:56 foo kernel: [ 1042.540011] bonding: bond0: link status down for interface eth1, disabling it in 200 ms.
Jun 20 12:33:56 foo kernel: [ 1042.740015] bonding: bond0: link status definitely down for interface eth1, disabling it
Jun 20 12:33:56 foo kernel: [ 1042.740021] device eth0 entered promiscuous mode
Jun 20 12:33:56 foo kernel: [ 1042.740435] e1000e: eth0 NIC Link is Down
Jun 20 12:33:56 foo kernel: [ 1042.840015] bonding: bond0: link status down for interface eth0, disabling it in 200 ms.
Jun 20 12:33:57 foo kernel: [ 1043.040009] bonding: bond0: link status definitely down for interface eth0, disabling it
Jun 20 12:33:57 foo kernel: [ 1043.040687] device eth0 left promiscuous mode
Jun 20 12:33:57 foo kernel: [ 1043.040913] bonding: bond0: now running without any active interface !
Jun 20 12:33:57 foo kernel: [ 1043.230020] bonding: bond0: Error: found a client with no channel in the client's hash table
Jun 20 12:33:57 foo kernel: [ 1043.270668] bonding: bond0: Error: found a client with no channel in the client's hash table
[...]

Maybe someone can check and confirm this behaviour. Unfortunately, all of my servers are productive. I had to change them back to single NIC operation to get them accessible again. I cannot do any further tests with my environment.

Regards from Berlin/Germany
Karsten