Second / Third Network Device not active..

elytrn

Member
Feb 22, 2017
9
0
6
34
Hello,
I'm new to Proxmox and i tried to setup my network configuration, but every time i try it, all deviced exclusive the fist one are not active. I guess I have a little mistake at my configuration but I didnt find it.

This is my configuration from /etc/network/interfaces:
picture1.png

I tried the command "ifup eth0 - ifup eth1 - ifup eth2", but at the Proxmox Interface still marked as not active.

Here a Screenshort from my Proxmox Interface:
picture2.png
I host my server ony hetzner, with 3 IP addresses, if im hoving over one IP it show me this (same thing on every IP):
pircure3.png

I can create a seperate MAC for every IP if i need this.
I'm really new to networking at stuff like this (I'm a noob), but I hope anyone can help me with my problem! :)
 
Last edited:
are these devices connected to an ethernet network ?

do you see them when doing

ip link show up
 
are these devices connected to an ethernet network ?

do you see them when doing

ip link show up
Hello manu,
first of all thanks for your answer!
I dont know how can I check if they connected to an ethernet network.
I just bought additional IP's from Hetzner.

This is the result if I type "ip link show up":
root@proxmox ~ # ip link show up
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master vmbr0 state UP mode DEFAULT group default qlen 1000
link/ether c8:60:00:df:06:05 brd ff:ff:ff:ff:ff:ff
3: vmbr0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DEFAULT group default qlen 1000
link/ether c8:60:00:df:06:05 brd ff:ff:ff:ff:ff:ff
4: vmbr1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
link/ether 76:d3:33:c6:d7:f5 brd ff:ff:ff:ff:ff:ff
5: vmbr2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
link/ether aa:7d:ab:04:46:79 brd ff:ff:ff:ff:ff:ff
 
Ok if you bought these IP, you don't need to create extra bridges on the Proxmox Host with the extra IP, you will use theses IP in the *guest* virtual machine.
 
Ok if you bought these IP, you don't need to create extra bridges on the Proxmox Host with the extra IP, you will use theses IP in the *guest* virtual machine.

How do i do this? When i edit/create my maschine i cant pick a direct eth* i need to pick a bridge...
 
pulled this information from the hetzner documentation:

https://wiki.hetzner.de/index.php/Zusaetzliche_IP-Adressen/en

Code:
Individual addresses
The assigned addresses can be configured as additional addresses on the network interface. To ensure the IP addresses are configured after a restart, the corresponding configuration files of the operating system/distribution need to be adjusted accordingly. Further details can be found on the pages for Debian/Ubuntu and CentOS.

Add an (additional) IP address:

ip address add 192.0.2.92/32 dev eth0

Alternatively, it can be forwarded within the server (e.g. for virtual machines):

ip route add 192.0.2.92/32 dev tap0
# or
ip route add 192.0.2.92/32 dev br0

The corresponding virtual machines have to use the main IP address of the server as the default gateway.

ip route add 192.0.2.84 dev eth0
ip route add default via 192.0.2.84

When forwarding the IP ensure that IP forwarding is enabled:

sysctl -w net.ipv4.ip_forward=1

If a separate MAC address has been set for the IP address via the Robot, then the corresponding gateway of the IP address needs to be used.

You need to add the extra ip addresses to the eth0 interface, this creates an alias like => eth0:0 in case you need this address on your proxmox.

If you want your extra ip address assigned to a VM you need to bridge eth0 with your vmbr0 and assign your primary public ip to this bridge, like you already did. after this, you can bridge your VM to you VMBR0 and assign them you extra ip's with as gateway you primary public ip.

As you are new to networking I recommend to first assign the extra ip's to the proxmox node to interface eth0:0 and maybe eth0:1 and try to ping these from your home. if these are reachable you can move on configuring.
 
pulled this information from the hetzner documentation:

https://wiki.hetzner.de/index.php/Zusaetzliche_IP-Adressen/en

Code:
Individual addresses
The assigned addresses can be configured as additional addresses on the network interface. To ensure the IP addresses are configured after a restart, the corresponding configuration files of the operating system/distribution need to be adjusted accordingly. Further details can be found on the pages for Debian/Ubuntu and CentOS.

Add an (additional) IP address:

ip address add 192.0.2.92/32 dev eth0

Alternatively, it can be forwarded within the server (e.g. for virtual machines):

ip route add 192.0.2.92/32 dev tap0
# or
ip route add 192.0.2.92/32 dev br0

The corresponding virtual machines have to use the main IP address of the server as the default gateway.

ip route add 192.0.2.84 dev eth0
ip route add default via 192.0.2.84

When forwarding the IP ensure that IP forwarding is enabled:

sysctl -w net.ipv4.ip_forward=1

If a separate MAC address has been set for the IP address via the Robot, then the corresponding gateway of the IP address needs to be used.

You need to add the extra ip addresses to the eth0 interface, this creates an alias like => eth0:0 in case you need this address on your proxmox.

If you want your extra ip address assigned to a VM you need to bridge eth0 with your vmbr0 and assign your primary public ip to this bridge, like you already did. after this, you can bridge your VM to you VMBR0 and assign them you extra ip's with as gateway you primary public ip.

As you are new to networking I recommend to first assign the extra ip's to the proxmox node to interface eth0:0 and maybe eth0:1 and try to ping these from your home. if these are reachable you can move on configuring.


Hello,
I tried to add the IP addresses to eth0 but I guess I did something wrong, the adresses wont show up and I cant create bridges on proxmox anymore... if I try to create a bridge and reboot the server my whole network is fu*** up. So i resettet the whole server, i have now a clean installed version from proxmox 4.4.
The dedicated server got the following network:
IP: 5.x.x.205
Netmask: 255.255.255.224
Gateway: 5.x.x.193
Broadcast: 5.x.x.223

I bought 2 additional IP's for my server:
IP: 5.x.x.220 and 5.x.x.221
Netmask: both 255.255.255.224
Gateway: both 5.x.x.193
Broadcast: 5.x.x.223
MAC: 00:50:56:00:01:A3 and 00:50:56:00:C4:B7

(Pulled this information from hetzner)

If I'm understanding right i need to do the following:
open the /etc/network/interfaces and add:

auto eth0:0
iface eth0:0 inet static
address 5.x.x.220
netmask 255.255.255.224

The same for eth0:1 and then ifup "eth0:0" and ifup "eth0:1".
picture1.png

After adding them Proxmox show me every time "Type unknown", if i add them as eth1 and eth2 they will be "type network device"..
I dont understand what i need todo, please help me with it. :/
 
#Edit:

I tried the following:
I added my second IP Address to my primary server with "ip address add 5.xx.xx.220/27 dev eth0", then i added a network bridge on proxmox:
picture1.png

After this i gave the bridge to my vm and configurated the network on my vm.
picture2.png

Until this, the default gateway is 5.xx.xx.193, i can reach my server via ping and ssh, but if i try something like "portsnap fetch extract" i get an error (no internet connection)... if I change the gateway to 5.xx.xx.205 (primary IP) i cant ping my server anymore.
 
If you bridge your eth0, you normally give the vmbr0 an ip and not the eth0 => this can lead to strange network behaviour.


for the proxmox:
I noticed you added the extra ip's with a /27 subnet or 255.255.255.224. I think you should add your extra addresses with a /32 or 255.255.255.255 subnet, like hetzner prescribes. => their command to add extra ip to eth0(changed to your case) = ip address add 5.x.x.220/32 dev eth0
This will add eth0:0 wit your ip. If you assigned the ip to your server through the hetzner portal you shouldn't worry about the routing an the /32 subnet, hetnzer takes care this. Try this and try to ping it from home or something like that.

If you want to give a VM also a public and above eth0:0 works. Connect vmbr0 to your eth0:0 and VM, and assign your 5.x.x.221 address to your VM as gateway the 5.x.x.220 addres of the bridge.

With my host i got almost the same setup, i followed this config. looks almost the same: https://support.packet.net/en/suppo...22000057525-how-to-configure-a-network-bridge
you can use this as base they use lo:0 you should use eth0:0.

In my configuration i ended up setting my subnetmask to 255.255.255.0 or a /24 to get it fully working => this was with 16 extra addresses

Maybe sending an email to hetzner will get you some valid information
 
I tried the following:
ip address add 5.x.x.220/32 dev eth0

Output from "ip address show":
picture1.png


Then i created a new vmbr:
picture2.png


After this I told my vm to use the bridge:
picture3.png


If I try to configure the network on my vm now, i always get the error "network is unreachable".
My configuration:
IP: 5.x.x.220
Netmask: 255.255.255.255
Gateway: 5.x.x.205


It work if i do the following:
On my primary machine: ip address add 5.x.x.220/27 dev eth0 and bridge eth0 it works fine, but i cant bridge more then one maschine over eth0... if i try to add an eth0:0 to the /etc/network/interfaces proxmox tell me "unknown device", if i add eth1 the device is not active and got no internet connection..
 
Last edited:
configure your eth0 with the 5.x.x.205 ip => this worked in the beginning.

bridge eth0:0 with vmbr0.
This cant be done through the proxmox gui but must be done in the network interfaces file, as proxmox gui doesn't handle the alias( eth0:0)

give the bridge the 5.x.x.220 address
Try pinging it externally, should work before moving on.

on your vm give it the 5.x.x.221 address and as gateway the 5.x.x.220



on proxmox (change as needed):
Code:
auto eth0
iface eth0 inet static
 your 5.x.x.205 ipaddress and subnet and gateway

auto eth:0
iface eth:0 inet manual

auto vmbr0
iface vmbr0 inet static
        address  5.x.x.220
        netmask  255.255.255.0 ( try this or 255.255.255.255)
        bridge_ports eth:0
        bridge_stp off
        bridge_fd 0

on your vm something like:

Code:
auto eth0
iface eth0 inet static
 your 5.x.x.221 ipaddress and subnet(255.255.255.0 because 255.255.255.255 will make your gateway unreachable) and gateway 5.x.x.220
 
Thanks again for your reply, i tried the config like you told me:
picture4.png


(I did nothing on eth0 because this was the default settings..)

Aswell i tried for vmbr0 as gateway 255.255.255.255 / 255.255.255.0 and 255.255.255.224, on all three i cant ping the IP (5.x.x.220)...
I dont know what i do wrong.
 
i can't help much further, i tried explaining like i would do it.
You can send an email to hetzner to get you a working example, I am sure they know their infrastructure a lot better then me.
 
i can't help much further, i tried explaining like i would do it.
You can send an email to hetzner to get you a working example, I am sure they know their infrastructure a lot better then me.

Thanks anyway, you tried your best. :)
I did it like you told me and I did it like the example from Hetzner... i dont know why but i cant use 255.255.255.255 (or with 0) as Netmask, the server isnt reachable after it.
 
With networking you can test part by part, :)
your eth0 works, then you can try get eth0:0 working with one ip. If this works fully (pinging,traceroute,..) you can try bridging or adding eth0:1 and work you way further.

Goodluck :)
 
With networking you can test part by part, :)
your eth0 works, then you can try get eth0:0 working with one ip. If this works fully (pinging,traceroute,..) you can try bridging or adding eth0:1 and work you way further.

Goodluck :)

I know a guy hosting his server at hetzner... they make it "easier" for you to do this... the only thing you need to do is to make 1 bridge with the data for the eth0 (eth0 need to be empty) and bridge vmbr0 to eth0... on a vm you need to enter the mac address for the additional ip.
No documentation from them... thank you anyway! :)
 

About

The Proxmox community has been around for many years and offers help and support for Proxmox VE, Proxmox Backup Server, and Proxmox Mail Gateway.
We think our community is one of the best thanks to people like you!

Get your subscription!

The Proxmox team works very hard to make sure you are running the best software and getting stable updates and security enhancements, as well as quick enterprise support. Tens of thousands of happy customers have a Proxmox subscription. Get yours easily in our online shop.

Buy now!