VMs in bonded+bridged host can't ping

[twainiak]

I've searched for hours and hours in threads trying to figure out why a newly made Ubuntu 20.4 VM can't ping even its host.

Proxmox host interfaces file, for two ethernet NICs bonded together:

auto lo
iface lo inet loopback
iface eno1 inet manual
iface eno2 inet manual

auto bond0
iface bond0 inet manual
        bond-slaves eno1 eno2
        bond-miimon 100
        bond-mode 802.3ad

auto vmbr0
iface vmbr0 inet static
        address 192.168.1.100/24
        gateway 192.168.1.1
        bridge-ports bond0
        bridge-stp off
        bridge-fd 0

The VM is Ubuntu 20.4 and using netplan, which I believe means the netplan config supersedes the interfaces file. Here's the netplan config:

network:
  version: 2
  renderer: networkd
  ethernets:
    ens18:
      dhcp4: no
      addresses: [192.168.1.101/24]
      gateway4: 192.168.1.1
      nameservers:
        addresses: [8.8.8.8]
      dhcp6: no

Host can ping just fine the gateway (192.168.1.1) and google.com
VM can ping itself (192.168.1.101), but NOT the host (192.168.1.100) or anything else.

What am I missing?

 

[twainiak]

If it is relevant, here's the VM interfaces file. It didn't initially have parameters like broadcast and dns-nameservers, I added that in an attempt to troubleshoot:

auto lo
face lo inet loopback
auto ens18
        iface ens 18 inet static
        address 192.168.1.101
        netmask 255.255.255.0
        broadcast 192.168.1.255
        gateway 192.168.1.1
        network 192.168.1.0
        dns-nameservers 8.8.8.8

And attached is the output of an "ip add" on the VM

 

[twainiak]

Hello all, would love any advice -- still struggling with this. I'm confused because it seems like a pretty vanilla configuration.

 

[aaron]

What is the VM config? qm config <vmid>
Do you have the firewall enabled for the node itself? Firewall -> Options in the Datacenter and node level.

 

[twainiak]

VM Config:

bootdisk: scsi0
cores: 6
ide2: local:iso/ubuntu-20.04.1-live-server-amd64.iso,media=cdrom
memory: 8096
name: ubuntu1
net0: virtio=5E:B9:32:C1:3F:5A,bridge=vmbr0,firewall=1
numa: 0
ostype: l26
scsi0: local-lvm:vm-100-disk-0,size=32G
scsihw: virtio-scsi-pci
smbios1: uuid=21dc48e0-0dc8-431f-9260-a8fefcdcd5e1
sockets: 1
vmgenid: 08b02114-a8f9-476b-8b25-bb77dedf45e7

Node firewall: was turned on. I turned it off, no help, still could not ping the host from the VM.
(And I'm confused as to why it says firewall=1 in the code above, but the Proxmox UI says Firewall=No for both node and VM.)

 

[ryba84]

Read this: https://access.redhat.com/documenta...ml/networking_guide/sec-using_channel_bonding

Does your switch support link aggregation? Try change hash policy, arp_interval.