No internet connectivity for VMs

[Reuven]

Hi and thanks for your help.

I have no networking for my first VM in my new Proxmox 6.2 installation.....here is my /etc/network/interfaces :

auto lo
iface lo inet loopback

iface enp8s0 inet manual

auto vmbr0
iface vmbr0 inet static
address 88.198.26.141/27
gateway 88.198.26.129
bridge-ports enp8s0
bridge-stp off
bridge-fd 0
bridge-vlan-aware yes
bridge-vids 2-4094

I need NAT and an DHCP server to assign private IPs to my VMs when they boot...

Thanks in advance

 

[Moayad]

Hi,

have you see our guide about Masquerading (NAT) with iptables?

 

[Reuven]

Hi. Thanks for your reply and help.

I did check Masquerading (NAT) with iptables?

but I am a little confused. let me explain:

in my /etc/network/interfaces the vmbr0 appears to have my only public IP address while in the Masquerading (NAT) with iptables the vmbr0 has the private subnet assigned to it....

(this is my /etc/network/interfaces)

auto lo
iface lo inet loopback

iface enp8s0 inet manual

auto vmbr0
iface vmbr0 inet static
address 88.198.26.141/27
gateway 88.198.26.129
bridge-ports enp8s0
bridge-stp off
bridge-fd 0
bridge-vlan-aware yes
bridge-vids 2-4094

but in the Masquerading (NAT) with iptables example it is the opposite

auto lo
iface lo inet loopback

auto eno1
#real IP address
iface eno1 inet static
address 198.51.100.5
netmask 255.255.255.0
gateway 198.51.100.1

auto vmbr0
#private sub network
iface vmbr0 inet static
address 10.10.10.1
netmask 255.255.255.0
bridge_ports none
bridge_stp off
bridge_fd 0

post-up echo 1 > /proc/sys/net/ipv4/ip_forward
post-up iptables -t nat -A POSTROUTING -s '10.10.10.0/24' -o eno1 -j MASQUERADE
post-down iptables -t nat -D POSTROUTING -s '10.10.10.0/24' -o eno1 -j MASQUERADE


Now, I ask, from the start my installation did not give my new VM internet connectivity, is this normal? or should i reinstall proxmox?

with any other virtualization solution, for example in Hyper-v, you get automatic nat and dhcp with the "Default switch"

also in vmware....that is why i ask...maybe there is something wrong with my installation...

all the best Reuven

 

[Reuven]

Just to add this information...maybe it is relevant... my server is hosted at hetzner ..I installed proxmox 6.2 using the proxmox ISO....

 

[r.jochum]

Reuven, Hetzner is very very relevanat, they block all mac addresses which is not the one from the host itself. You need to route through the host and maybe (from i heard) MTU 1400 on the bridge and inside the vm.

Please search the forum for Hetzner, you will find lots of infos.