Vitual Machine lost IPv6 route after a while

[BvO]

Hi,
I have a new setup with Proxmox 5.4. In this setup I have a virtual Ubuntu 18.04 LTS machine. I set up IPv4 and IPv6 next to eachother. After while (mostly a day) I lose the IPv6 route.
By reading here and on the internet with google, i am not sure what to do about this.
I got a few public IP4 adresses and a /64 IPv6 range from the provider.

This is my config in Proxmox:
****************************************
auto lo
iface lo inet loopback

iface eno1 inet manual

auto vmbr0
iface vmbr0 inet static
address 6x.x.x.231
netmask 255.255.255.0
gateway 6x.x.x.1
bridge-ports eno1
bridge-stp off
bridge-fd 0
#For Proxmox

iface vmbr0 inet6 static
address 2a00:x:x:x::231
netmask 64
gateway 2a00:x:x:x::1
***************************************
ip -6 route
2a00:x:x:x::/64 dev vmbr0 proto kernel metric 256 pref medium
fe80::/64 dev vmbr0 proto kernel metric 256 pref medium
default via 2a00:x:x:x::1 dev vmbr0 metric 1024 pref medium
***************************************
Settings in virtual machine Ubuntu 18.04 LTS

# This file describes the network interfaces available on your system
# For more information, see netplan(5).
network:
version: 2
renderer: networkd
ethernets:
ens18:
dhcp4: no
dhcp6: no
addresses: [ 6x.x.x.233/24, '2a00:x:x:x::233/64' ]
gateway4: 6x.x.x.1
gateway6: 2a00:x:x:x::1
nameservers:
search: [ my domain ]
addresses:
- "x.x.x.x"
- "2a00:x::x"
- "x.x.x.x"
*****************************
Any tips are welcome.
My IPv6 on the Proxmox server seems always to work, only not the IPv6 from the host.

Thanks in advance!

BvO

 

[Richard]

Hi,
I have a new setup with Proxmox 5.4. In this setup I have a virtual Ubuntu 18.04 LTS machine. I set up IPv4 and IPv6 next to eachother. After while (mostly a day) I lose the IPv6 route.
By reading here and on the internet with google, i am not sure what to do about this.
I got a few public IP4 adresses and a /64 IPv6 range from the provider.

Question: what exaclty disappears?

(a) the routing configuration inside the VM?
(b) the functionaltity of routing (but configuration is still correct)?


In case of (a) it's a topic which has to be investigated inside the VM

In case of (b) it's possibly caused by the provider which blocks sending packets to the VM's (virtual) interface since its MAC address is unknown and not accepted. In that case internal connections (i.e. between VM and host respectively VMs) sill work.

 

[BvO]

Thanks for answering.
It's option (b) the functionality off the routing in the VM disapears while the configuration is still valid. How can I solve this in the VM or in the host, that's the question.

 

[Richard]

Thanks for answering.
It's option (b) the functionality off the routing in the VM disapears while the configuration is still valid. How can I solve this in the VM or in the host, that's the question.

If it is what I suspected in the recent post the idea of https://www.ipsidixit.net/2010/03/24/239/ may help. But before going into more details figure out if local connections work and if outgoing packets are sent to the router correctly but never answered.