Ubuntu Server 20.04 on Proxmox VE unable to connect to internet

ravi kundu

New Member
Jan 25, 2022
6
0
1
23
Good day to everyone,

I am running a Ubuntu server on Proxmox VE , but i am unable to ping to 8.8.8.8 from my Ubuntu server. I am able to ping to Proxmox VE.

My /etc/network/interfaces for proxmox :

auto lo
iface lo inet loopback

auto enp0s3
iface enp0s3 inet manual

auto vmbr0
iface vmbr0 inet static
address 192.168.2.214/24
gateway 192.168.2.1
bridge-ports enp0s3
bridge-stp off
bridge-fd 0

and my /etc/netplan/00-installer-config.yaml:

network:
ethernets:
ens18:
addresses:
- 192.168.2.234/24
gateway4: 192.168.2.1
nameservers:
addresses:
- 8.8.8.8
- 8.8.4.4
version: 2

Any help is appreciated!!
Regards
 

oguz

Proxmox Staff Member
Staff member
Nov 19, 2018
4,895
616
118
hi,

is the PVE on a bare metal machine?

can you ping the gateway 192.168.2.1 from the ubuntu VM?
 

ravi kundu

New Member
Jan 25, 2022
6
0
1
23
Hi thanks for the reply,

No the PVE in on Virtualbox and i am unable to ping to 192.168.2.1

Ping Gives :
From 192.168.2.234 icmp_seq=50 Destination Host Unreachable
From 192.168.2.234 icmp_seq=51 Destination Host Unreachable
From 192.168.2.234 icmp_seq=52 Destination Host Unreachable
 

oguz

Proxmox Staff Member
Staff member
Nov 19, 2018
4,895
616
118
No the PVE in on Virtualbox and i am unable to ping to 192.168.2.1
you need to enable mac spoofing / promiscuous mode or however it might be called in virtualbox then ;)
with nested virtualization you usually need to do that when using bridged setups

also you should mention the virtualbox in the beginning :)

hope this helps
 
Last edited:

ravi kundu

New Member
Jan 25, 2022
6
0
1
23
I have changed the promiscuous Mode to Allow VMs and restart the server but still ping to 8.8.8.8 in giving :
From 192.168.2.234 icmp_seq=1 Destination Host Unreachable
From 192.168.2.234 icmp_seq=2 Destination Host Unreachable
From 192.168.2.234 icmp_seq=3 Destination Host Unreachable
 

oguz

Proxmox Staff Member
Staff member
Nov 19, 2018
4,895
616
118
@oguz and other changes or methods you can suggest please
we don't do virtualbox support here :) you could try rebooting everything :D

the PVE networking should work out of the box (your configuration looks fine to me)

you can check the ip a && ip r output inside the ubuntu VM to make sure the routes are correct.

in case of doubt you can run a tcpdump on your PVE host to see if the ping packets are leaving:
Code:
tcpdump -envi enp0s3 icmp

and while that's running try pinging internal/external hosts inside the VM. if you see the ICMP packets showing up then it's not a PVE problem :)
 

ravi kundu

New Member
Jan 25, 2022
6
0
1
23
@oguz can you help me with this please. Will changing my /etc/resolv.conf or /etc/hosts help?

(i)
/etc/resolv.conf :

nameserver 127.0.0.53
options edns0 trust-ad

(ii)
/etc/hosts :
127.0.0.1 localhost
127.0.1.1 ubuntu-server

# The following lines are desirable for IPv6 capable hosts
::1 ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
 

oguz

Proxmox Staff Member
Staff member
Nov 19, 2018
4,895
616
118
Will changing my /etc/resolv.conf or /etc/hosts help?
if you can't even ping your gateway then that won't make any difference... (those are DNS related settings)

@oguz can you help me with this please.
if you need help then i've explained above what you can check :)
 

ravi kundu

New Member
Jan 25, 2022
6
0
1
23
tcpdump -envi enp0s3 icmp
when i try running this command on PVE and try to ping 8.8.8.8 from ubuntu server i am getting :

21:22:17.611006 9e:b1:1d:b8:cd:6d > fc:7c:02:00:ca:78, ethertype IPv4 (0x0800), length 98: (tos 0x0, ttl 64, id 14180, offset 0, flags [DF], proto ICMP (1), length 84)
192.168.2.234 > 8.8.8.8: ICMP echo request, id 6, seq 3, length 64
21:22:17.611418 98:01:a7:8c:bc:49 > fc:7c:02:00:ca:78, ethertype IPv4 (0x0800), length 98: (tos 0x0, ttl 64, id 14180, offset 0, flags [DF], proto ICMP (1), length 84)
192.168.2.234 > 8.8.8.8: ICMP echo request, id 6, seq 3, length 64
21:22:18.619993 9e:b1:1d:b8:cd:6d > fc:7c:02:00:ca:78, ethertype IPv4 (0x0800), length 98: (tos 0x0, ttl 64, id 14366, offset 0, flags [DF], proto ICMP (1), length 84)
192.168.2.234 > 8.8.8.8: ICMP echo request, id 6, seq 4, length 64

i am new to all this. If can help please
 
Last edited:

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 your own in 60 seconds.

Buy now!