[PVE-User] proxmox2 bridge ip alias

THe_ZiPMaN flavio-pve at zipman.it
Sat Jul 28 23:13:41 CEST 2012


On 07/28/2012 09:38 PM, Stefan wrote:
> Hello all,
> I want  a second net on an interface and trying without luck by editing 
> /etc/network/ interfaces:
> 
> auto vmbr00
> iface vmbr00 inet static
>         address  10.100.221.1
>         netmask  255.255.255.0
>         gateway  10.100.221.254
>         bridge_ports eth0:0
>         bridge_stp off
>         bridge_fd 0
> 
> wenn I use vmbr0:0 seems to work. 
> 
> auto vmbr0:0
> iface vmbr0:0 inet static
>         address  10.100.221.1
>         netmask  255.255.255.0
>         gateway  10.100.221.254
>         bridge_ports eth0:0
>         bridge_stp off
>         bridge_fd 0
> 
> I can do ping -I vmbr0:0 to the world.

It seems to me that there are other errors too... i.e. eth0:0 shouldn't
be joined to the bridge.

> But using this I dont have it in 
> webinterface and cant use it for vm's. Cause the "colon" is not accepted in 
> gui config.

Wait. I think you are just a bit confused... In the web interface you
choose the BRIDGE to which the VMs' nics will be connected. Bridge is a
level 2 concept, not a level 3. You can have a bridge without any IP and
that's fine. You can think to a bridge as a switch that comprise the
physical interface on the host and the virtual interfaces of the VMs.

> Tried alot of things and searching but can not find a solution.

Maybe if you describe your setup and what you would need, it's simpler
to help.

> What is the correct way having multiple net's on a nic, each useable for 
> vm's??

If you need multiple subnet on the same physical network you can do as
you were doing, assigning multiple secondary ips to the bridge.
Usually I prefer to use the ip utils to accomplish this task

auto vmbr0
iface vmbr0 inet static
         address  10.100.221.1
         netmask  255.255.255.0
         gateway  10.100.221.254
         bridge_ports eth0
         bridge_stp off
         bridge_fd 0
         up ip addr add 10.100.222.1/24 dev vmbr0 || true
         up ip addr add 10.100.223.1/24 dev vmbr0 || true
         down ip addr del 10.100.222.1/24 dev vmbr0 || true
         down ip addr del 10.100.223.1/24 dev vmbr0 || true


Instead if you want more physical network you must create multiple
bridge, but in this case you must setup routing. Indeed I usually prefer
this latter setup.

So in /etc/network/interfaces you will find something like this:

###########################
auto lo
iface lo inet loopback

auto eth0
iface eth0 inet static
	address 192.168.10.1
	netmask 255.255.255.0
	gateway 192.168.10.254

auto vmbr0
iface vmbr0 inet static
	address 10.0.0.1
	netmask 255.255.255.0
	bridge_ports none
	bridge_stp off
	bridge_fd 0

auto vmbr1
iface vmbr1 inet static
	address 10.0.10.1
	netmask 255.255.255.0
	bridge_ports none
	bridge_stp off
	bridge_fd 0

auto vmbr2
iface vmbr2 inet static
	address 10.0.20.1
	netmask 255.255.255.0
	bridge_ports none
	bridge_stp off
	bridge_fd 0

###########################

And of course in /etc/sysctl.conf you will have something like this

###########################

net.ipv4.conf.all.rp_filter=1
net.ipv4.icmp_echo_ignore_broadcasts=1

net.ipv4.conf.all.forwarding = 1
net.ipv4.conf.default.forwarding=1

net.ipv6.conf.all.forwarding = 1
net.ipv6.conf.default.forwarding = 1

###########################

In this case I strongly recommend to setup a firewall and of course the
best choice are shorewall and shorewall6, for ipv4 and ipv6
respectively. A simple "everything open" setup for ipv4 can be as simple
as creating the following files

###########################
# /etc/shorewall/zones
fw	firewall
net	ipv4
virt	ipv4

###########################
# /etc/shorewall/interfaces
net	eth0		-		
virt	vmbr0		-		bridge,optional
virt	vmbr1		-		bridge,optional

###########################
# /etc/shorewall/policy
fw	all	ACCEPT
virt	net	ACCEPT
virt	all	REJECT
all	all	REJECT

###########################
# /etc/shorewall/macro.Proxmox
PARAM   -       -       tcp	80,443,8006

###########################
# /etc/shorewall/rules
Ping(ACCEPT)	all	fw
Proxmox(ACCEPT)	net	fw
SSH(ACCEPT)	net	fw



-- 
Flavio Visentin

A computer is like an air conditioner,
it stops working when you open Windows



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