unrealservers failover ip config problems

BetaRacks

Hi

I ordered a server from unrealservers
I get ip a.b.c.120~a.b.c.125
netmask:255.255.255.255
gateway:100.64.20.141

I install pve7 on the server and assign a.b.c.120 to vmbr0
The server is working fine

When I created a vm to install alpine linux and did not assign a.b.c.121 to the vm, the system did not generate a route because the gateway and ip were not in the same cidr

So I tried ip route add default via 100.64.20.141 dev eth0 onlink

But vm still can't access the network, even can't ping a.b.c.120

When I try to capture the network packets via tcpdump
I found that when vm ping 1.1.1.1
will generate arp request (1.1.1.1 tell a.b.c.121)

I suspect that unrealservers is using mac filtering
I opened a ticket, but the staff replied me that they are not using mac filtering and suggested me to turn off br's stp
When I turned off the stp, the problem was still not solved

I don't know how to continue to troubleshoot this problem

Does anyone else have the same problem?
Can anyone give me some advice?

@UnrealServers

AlwaysSkint

I've never had an issue with their additional IPs but my setup won't necessarily help you. Here's an extract:

iface enp1s0 inet manual

auto int1
iface int1 inet static
address 192.168.10.2/24
ovs_type OVSIntPort
ovs_bridge vmbr1

auto vmbr0
iface vmbr0 inet static
address xxx.xxx.x5.18/29
gateway xxx.xxx.x5.17
bridge-ports enp1s0
bridge-stp off
bridge-fd 0

auto vmbr1
iface vmbr1 inet static
address 192.168.10.1/24
ovs_type OVSBridge
ovs_ports int1

ip r

default via xxx.xxx.x5.17 dev vmbr0 proto kernel onlink
xxx.xxx.x5.16/29 dev vmbr0 proto kernel scope link src xxx.xxx.x5.18
192.168.10.0/24 dev vmbr1 proto kernel scope link src 192.168.10.1
192.168.10.0/24 dev int1 proto kernel scope link src 192.168.10.2

On a client VM:

2: ens18: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
link/ether 2a:39:8a:8d:cc:71 brd ff:ff:ff:ff:ff:ff
inet xxx.xxx.x5.19/24 brd xxx.xxx.x5.255 scope global ens18
valid_lft forever preferred_lft forever

ip r

default via xxx.xxx.x5.17 dev ens18 onlink
xxx.xxx.x5.0/24 dev ens18 proto kernel scope link src xxx.xxx.x5.19

Note the default gateway, in particular. (I didn't manually specify the MAC.)
This might give you some clues.
Vanilla formatting is pissing me off, as usual - already tried code tags.