Problem creating Proxmox bridge in VPS with only one ip address

cdh

New Member
May 11, 2020
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First I apologize for my bad English.
After more than 1 week trying to install Proxmox 6 on a VPS server, I was able to install it.
In this VPS I only have 1 ip address, I run into the problem that when I try to create a "Linux bridge" and restart the machine, I lose access to Proxmox and my VPS.
Having to reinstall my machine and Proxmox again ... I have already tried many times and I am desperate, I don't know how to do it to avoid problems.

I have a VPS with a unique ip address and I want to create a network for the machines that I create in Proxmox.
The network that I want to create with the machines would be of type 192.168.10.1-254.
I do not have much computer knowledge and I would like, if it is possible that someone explained to me step by step how to create the bridge to connect the machines to the internet.
Thanks
 
hi,

In this VPS I only have 1 ip address, I run into the problem that when I try to create a "Linux bridge" and restart the machine, I lose access to Proxmox and my VPS.

most likely you misconfigured something and server lost connectivity as a result.

I have a VPS with a unique ip address and I want to create a network for the machines that I create in Proxmox.
The network that I want to create with the machines would be of type 192.168.10.1-254.

to achieve this, you can take a look at our network configuration guide. to quote from there:

Proxmox VE server at hosting provider, with a single public IP address
In that case the only way to get outgoing network accesses for your guest systems is to use Masquerading. For incoming network access to your guests, you will need to configure Port Forwarding.
For further flexibility, you can configure VLANs (IEEE 802.1q) and network bonding, also known as "link aggregation". That way it is possible to build complex and flexible virtual networks.

so the relevant part for you will be here[0]. you can edit the /etc/network/interfaces file as described and adapt the IP addresses based on what you have from your hosting provider.

hope this helps!

[0]: https://pve.proxmox.com/wiki/Networ...ith_tt_span_class_monospaced_iptables_span_tt
 
hi.
I've been following this conversation and many others on the same subject.
I think I followed the configuration procedure, but in the end, my VMs don't have internet access.

the Host Proxmox is connected to the Datacenter router on eth0
vmbr0 is associated with eth0

I created vmbr1 for virtual machines

here is the configuration /network/interfaces :

interfaces.png

here is ip route of the host.

iproute.png

I think it's a Masquerad probleme beacause NSLOOKUP works from the VM, and both ProxMox host and VM can ping each other (thanks to firewall rules of course)

ip config of the VM :
ip : 192.168.0.1/24
DW : 192.168.0.254
DNS : 192.168.0.254

nslookup.png

i've created a Datacenter firewall rule, witch autorize Everywhere to 192.168.0.0/24 (diagnostic purpose).

don't understand where i m wrong.

if somebody have idea. thanks in advance.
 
hi.
I've been following this conversation and many others on the same subject.
I think I followed the configuration procedure, but in the end, my VMs don't have internet access.

the Host Proxmox is connected to the Datacenter router on eth0
vmbr0 is associated with eth0

I created vmbr1 for virtual machines

here is the configuration /network/interfaces :

View attachment 17171

here is ip route of the host.

View attachment 17172

I think it's a Masquerad probleme beacause NSLOOKUP works from the VM, and both ProxMox host and VM can ping each other (thanks to firewall rules of course)

ip config of the VM :
ip : 192.168.0.1/24
DW : 192.168.0.254
DNS : 192.168.0.254

View attachment 17173

i've created a Datacenter firewall rule, witch autorize Everywhere to 192.168.0.0/24 (diagnostic purpose).

don't understand where i m wrong.

if somebody have idea. thanks in advance.

my settings

auto eth0
#real IP address
iface eth0 inet static
address X.X.X.X
netmask 255.255.255.0
gateway X.X.X.X

auto vmbr0
#private sub network
iface vmbr0 inet static
address 192.168.10.1
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 '192.168.10.0/24' -o eth0 -j MASQUERADE
post-down iptables -t nat -D POSTROUTING -s '192.168.10.0/24' -o eth0 -j MASQUERADE

without doing anything else the containers have internet access.
In each container I put as gateway 192.168.10.1 which is the one that is associated in the network bridge.

No gateway to be put on the bridge
 
Last edited:
my settings

auto eth0
#real IP address
iface eth0 inet static
address X.X.X.X
netmask 255.255.255.0
gateway X.X.X.X

auto vmbr0
#private sub network
iface vmbr0 inet static
address 192.168.10.1
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 '192.168.10.0/24' -o eth0 -j MASQUERADE
post-down iptables -t nat -D POSTROUTING -s '192.168.10.0/24' -o eth0 -j MASQUERADE

without doing anything else the containers have internet access.
In each container I put as gateway 192.168.10.1 which is the one that is associated in the network bridge.

No gateway to be put on the bridge

Bridge

1589484671333.png

network container

1589484518305.png
 
Last edited:
hi,
it works now.
don't really understand where i was wrong, re-do config vmbr1 from scratch

interfaces.png
 
I have switched from VPS, reinstalled proxmox (PVE Manager version pve-manager / 6.2-4 / 9824574a ) and doing the same now does not work either in the old (new installation) or in the new one. Has anything changed in the new version of proxmox? In the Vps that worked I have put exactly the same thing that I put and it worked, but now the containers are again without internet connection :mad:
 
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Reactions: lps90
hi,

the following configuration stopped working for me after an upgrade (kernel 5.4, I believed) :

Code:
iface enp1s0 inet manual

auto vmbr0
iface vmbr0 inet dhcp
        bridge-ports enp1s0
        bridge-stp off
        bridge-fd 0

auto vmbr1
iface vmbr1 inet static
        address 10.0.0.1/30
        bridge-ports none
        bridge-stp off
        bridge-fd 0

auto vmbr2
iface vmbr2 inet static
        address 192.168.9.1/24
        bridge-ports none
        bridge-stp off
        bridge-fd 0

The problem: iptables masquerading was only translating address for out-packets but in-packets were never dispatched to vmbr1 (tcpdump).
I reinstalled the VPS, thinking I made a mistake in the configuration or whatever but no luck. I reverted to kernel 5.0, no luck either.

The workaround I found : remove vmbr0 from /etc/network/interfaces and attach VPS IP to enp1s0 then nat of 10.0.0.0 network worked again.

Code:
auto enp1s0
iface enp1s0 inet dhcp

Other interfaces remain unchanged.

-
 
Last edited:
@Nicolas S can you explain in detail what to do inside the proxmox v6.2 network?
I am a little bit "noob", so i need a best explanation..

My proxmox v5.4 containers are working ok with this configuration:
1590018903439.png
1590019510853.png
**I just have 1 ipv4

Now i have a new dedicated with proxmox v6.2 and the same configuration is not working!
Can anybody explain how i can solve this problem?

Thanks
 
Last edited:
@lps90, did you also remove the physical port from vmbr0 like I did ?

No, i added the external ip and gateway to vmbr0, created a vmbr1 with the 192.168.0.1/24 ip and restarted the dedicated ;)
I use vmbr1 to all my containers and ipv4 is pinging with no problems (the only problem is ipv6 not pinging in containers)

1590085488010.png
 
My host is pinging ipv4/ipv6 with no problems, my containers are pinging ipv4, but not ipv6.
Anyone that can help with ipv6 configuration in containers?
I'm searching and searching for a solution, but no lucky..
#I'm loosing hope here..
 

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