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Proxmox - Troubleshooting - No internet on VM

Installed Ubuntu Server 20.04, but no Internet.

During the install of Ubuntu it gets to networking, where it reports no networking found.

Can ping the Proxmox host, but nothing else.

Check PCI devices

lspci | grep Ethernet

returns: 

03:00.0 Ethernet controller: Intel Corporation Device 15f3 (rev 02)

Does the NIC support bridge mode with the default driver

On the Proxmox host: 

brctl show

returns: 

bridge name bridge id         STP enabled interfaces
vmbr0       8000.a8a1592fb8a6 no          enp3s0

NOTE: A newer driver might need to be compiled to get bridge mode supported.

Check udev

udevadm info /sys/class/net/vmbr0

returns: 

P: /devices/virtual/net/vmbr0
L: 0
E: DEVPATH=/devices/virtual/net/vmbr0
E: DEVTYPE=bridge
E: INTERFACE=vmbr0
E: IFINDEX=5
E: SUBSYSTEM=net
E: USEC_INITIALIZED=188415741
E: ID_NET_NAMING_SCHEME=v240
E: ID_NET_DRIVER=bridge
E: ID_NET_LINK_FILE=/usr/lib/systemd/network/99-default.link
E: ID_NET_NAME=eth0
E: SYSTEMD_ALIAS=/sys/subsystem/net/devices/eth0
E: TAGS=:systemd:
cat /usr/lib/systemd/network/99-default.link

returns: 

#  SPDX-License-Identifier: LGPL-2.1+
#
#  This file is part of systemd.
#
#  systemd is free software; you can redistribute it and/or modify it
#  under the terms of the GNU Lesser General Public License as published by
#  the Free Software Foundation; either version 2.1 of the License, or
#  (at your option) any later version.
 
[Link]
NamePolicy=keep kernel database onboard slot path
MACAddressPolicy=persistent

Check the Journal

journalctl -b -u systemd-networkd.service -u systemd-udevd.service --no-hostname

returns: 

Mar 10 07:11:36 systemd[1]: Starting udev Kernel Device Manager...
Mar 10 07:11:36 systemd[1]: Started udev Kernel Device Manager.
Mar 10 07:11:36 systemd[1]: Starting Network Service...
Mar 10 07:11:36 systemd-udevd[296]: link_config: autonegotiation is unset or enabled, the speed and duplex are n
Mar 10 07:11:37 systemd-networkd[269]: Enumeration completed
Mar 10 07:11:37 systemd-networkd[269]: lo: Removing non-existent address: ::1/128 (valid forever), ignoring
Mar 10 07:11:37 systemd[1]: Started Network Service.
Mar 10 07:11:37 systemd-udevd[279]: Using default interface naming scheme 'v240'.
Mar 10 07:11:37 systemd-networkd[269]: eth0: Gained carrier
Mar 10 07:11:37 systemd-networkd[269]: eth0: Could not bring up interface: Invalid argument
Mar 10 07:11:37 systemd-networkd[269]: eth0: could not set address: Permission denied

NOTE: The following messages seems interesting:

  • link_config: autonegotiation is unset or enabled, the speed and duplex are n.
  • Using default interface naming scheme 'v240'.
  • eth0: Could not bring up interface: Invalid argument.
	Supported ports: [ ]
	Supported link modes:   10baseT/Half 10baseT/Full 
	                        100baseT/Half 100baseT/Full 
	                        1000baseT/Full 
	                        2500baseT/Full 
	Supported pause frame use: Symmetric
	Supports auto-negotiation: Yes
	Supported FEC modes: Not reported
	Advertised link modes:  10baseT/Half 10baseT/Full 
	                        100baseT/Half 100baseT/Full 
	                        1000baseT/Full 
	                        2500baseT/Full 
	Advertised pause frame use: Symmetric
	Advertised auto-negotiation: Yes
	Advertised FEC modes: Not reported
	Speed: 1000Mb/s
	Duplex: Full
	Port: Twisted Pair
	PHYAD: 0
	Transceiver: internal
	Auto-negotiation: on
	MDI-X: off (auto)
	Current message level: 0x00000007 (7)
			       drv probe link
	Link detected: yes