MAC of multiple virtual machines change

[harmonyp]

arp -a output shows the following

ipxxx.ip-51-89-201.eu (51.89.201.xxx) at fe:ed:de:ad:be:ef [ether] on vmbr0

After rebooting the VM (MAC returns correctly)

ipxxx.ip-51-89-201.eu (51.89.201.xxx) at 02:00:00:9b:81:48 [ether] on vmbr0

What could be the cause of this? It seems to happen to multiple machines at the same time and always the same MAC. I have found that the MAC is used by the gateway IP

? (51.195.234.254) at fe:ed:de:ad:be:ef [ether] on vmbr0

The nodes network

auto lo
iface lo inet loopback


auto enp193s0f0
iface enp193s0f0 inet manual


auto enp133s0f0
iface enp133s0f0 inet manual


auto enp133s0f1
iface enp133s0f1 inet manual


auto enp193s0f1
iface enp193s0f1 inet manual


iface enp9s0f3u2u2c2 inet manual


auto bond0
iface bond0 inet manual
    bond-slaves enp193s0f0 enp193s0f1
    bond-miimon 100
    bond-mode 802.3ad
    bond-xmit-hash-policy layer2+3


auto bond1
iface bond1 inet manual
    bond-slaves enp133s0f0 enp133s0f1
    bond-miimon 100
    bond-mode 802.3ad
    bond-xmit-hash-policy layer2+3


auto vmbr0
iface vmbr0 inet static
    address 51.195.234.xxx/24
    gateway 51.195.234.254
    bridge-ports bond0
    bridge-stp off
    bridge-fd 0




    post-up ip route add 51.89.201.xxx/28 dev vmbr0
    post-up echo 1 >/proc/sys/net/ipv4/ip_forward

The virtual machine is configured to use

51.89.201.xxx/32
GW 10.0.10.1

It has even done this to a virtual machine that has been shut down for several days.

 

[spirit]

" fe:ed:de:ad:be:ef " -> feed dead beef ?

sound like something is flooding your network with gratuitous arp, or some kind of attack or joke

 

[harmonyp]

" fe:ed:de:ad:be:ef " -> feed dead beef ?

sound like something is flooding your network with gratuitous arp, or some kind of attack or joke

Didn't see that but no don't think so I have another server with nothing on it with OVH and it retrurns

? (51.195.234.254) at fe:ed:de:ad:be:ef [ether] on vmbr0

or it's an issue on OVH end

 

[harmonyp]

Any suggestion on a fix for this?

I have tried adding

net.ipv4.conf.vmbr0.arp_ignore=1
net.ipv4.conf.vmbr0.arp_announce=2

To flush ARP cache I run the following which temporarily fixes

ip -s -s neigh flush all