New PVE install, no network for guest VM's

[jkaberg]

Fresh out of install trying to setup a VM on my PVE host, however the guest VM never receives any DHCP (DHCP exists on the network - the client I'm writing from has an DHCP IP from the same DHCP server as guest VM ). Setting static IP doesn't work either, it can't ping GW or similar.

Here is my /etc/network/interfaces

root@pve:~# cat /etc/network/interfaces
auto lo
iface lo inet loopback

iface enp1s0f0 inet manual

auto vmbr0
iface vmbr0 inet static
        address 192.168.1.5
        netmask 255.255.255.0
        gateway 192.168.1.1
        bridge_ports enp1s0f0
        bridge_stp off
        bridge_fd 0

iface enp1s0f1 inet manual
root@pve:~#

From the PVE host I have full access to the network and internet, no problem there.

Running the latest kernel and Promox,

Linux pve 4.10.17-2-pve #1 SMP PVE 4.10.17-20 (Mon, 14 Aug 2017 11:23:37 +0200) x86_64 GNU/Linux

Proxmox Virtual Environment 5.0-30

 

[manu]

check that:
* network connectivity is working via the vmbr0 device
( ping your gateway from the host_
* the virtual NIC of the vm is inside the vmbr0 bridge
brctl show vmbr0

shoud give you a list of devices on the bridge, of the form "tapMYVMIDi0"

* on the host start tcpdump on the bridge, looking a brodcast traffic (DHCP asks for an IP using a broadcast query)
tcpdump -i vmbr0 ether broadcast

* now manually start a DHCP client on the guest ( I use this on Linux
dhclient -i eth0
)

you should see on the host:
09:02:39.675717 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from 26:9a:6d:ee:2e:c2 (oui Unknown), length 300

where 26:9a:6d:ee:2e:c2 is the Mac address of the guest

 

[jkaberg]

check that:
* network connectivity is working via the vmbr0 device
( ping your gateway from the host_
* the virtual NIC of the vm is inside the vmbr0 bridge
brctl show vmbr0

shoud give you a list of devices on the bridge, of the form "tapMYVMIDi0"

* on the host start tcpdump on the bridge, looking a brodcast traffic (DHCP asks for an IP using a broadcast query)
tcpdump -i vmbr0 ether broadcast

* now manually start a DHCP client on the guest ( I use this on Linux
dhclient -i eth0
)

you should see on the host:
09:02:39.675717 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from 26:9a:6d:ee:2e:c2 (oui Unknown), length 300

where 26:9a:6d:ee:2e:c2 is the Mac address of the guest

I did a fresh install today and voila! It fixed itself

Thanks for the tip anyhow, will keep that in mind.

 

[proxbob]

Hi, I have the exact same problem.
I install a new centOS 6 or 7 as LXC container and it has no internet, can't even ping.

I followed manu's instructions and I see the dhcp requests on the host, what next ?

FYI, if in proxmox interface I change network device name (from eth0 to anything), the guest can connect to the internet, but once I reboot the guest, the connection is lost again, any idea ?