Network configuration with two NICs

[reetp]

Hi,

I just wondered if someone could give me some general networking advice.

Currently have 3.1 installed on a HP server with 2 network cards. On this machine I intend to run 2 VMs.

I would like the 'main' VM to have exclusive use of one network card (e.g. vmbr1/eth1) and leave the other (vmbr0/eth0) for 'everything else'.

I know this could be done with PCI passthrough for one card but I believe this can cause issues if you move the machine. Is there any way it can be done from the panel ?

Currently the panel shows this :

Name / Active / Autostart
eth0 / Yes / No
eth1 / No / No
vmbr0 / Yes / Yes / eth0 / 192.168.10.3 / 255.255.255.0 / 192.168.10.250


I tried to configure vmbr1 as follows :

vmbr1 / eth1 / 192.168.10.4 / 255.255.255.0 / 192.168.10.250

However I get 'default gateway already exists'. Why can't both vmbr ports have the same gateway IP - I only have one router as a gateway for the network ?


B. Rgds
John

 

[pirateghost]

The computer can only have ONE gateway.

You don't need to assign an IP to vmbr1. Just connect eth1 to it and activate it. On your VM connect it to vmbr1

Sent from my Galaxy Nexus

 

[reetp]

The computer can only have ONE gateway.

You don't need to assign an IP to vmbr1. Just connect eth1 to it and activate it. On your VM connect it to vmbr1

Hmmm. Thanks for the reply but I'm a bit lost.

As I mentioned, if I want to use both vbr0/eth0 and vbr1/eth1 I need to assign a separate IP address and gateway to vbr1 to link it to eth1 but I then have to use another gateway I which I don't have.... I only have one gateway IP address (no fancy routing here !).

Bearing in mind we have one REAL machine and however many 'VMs' then each should be able to have the same default gateway, just as you if you had x amount of real machines ?

Sorry to be so dumb - this ain't my strong suit

Be grateful for any education in the matter !

B. Rgds
John

 

[pirateghost]

You DO NOT need to put an IP address on vmbr1.

In fact, unless you have multiple subnets you should only have one IP address on your proxmox host.

A nic doesn't need an IP address in order for it to work. You assign eth1 to vmbr1. Reboot. Configure a VM to use vmbr1. The VM itself will get an IP address from either your dhcp server on the network or from you manually configuring an IP.

Try to think of your bridges as virtual switches. You can plug many machines into a virtual switch without their being an IP address on the actual switch.

Sent from my Galaxy Nexus

 

[reetp]

Ah, think I've got it now.

Having boxes to fill in for the IP address etc fooled me. Just added vmbr1 with bridge port as eth1 and left the other boxes blank. Think that should fix it.

Will see what happens - can't reboot til later.

B. Rgds
John