new server, VM network doesn't work

[Kimmo H]

Hi,
new to proxmox, have one testserver installed from .ISO which have 2 VM's running ok.

Second server i installed from Debian 9 and then Proxmox via APT, attached to same cluster as 2nd server, everything ok.

Then adding first VM for second server and cannot get network to work with it. I compare installations and see that second one was missing vmbr0 Linux Bridge. I added that via GUI and make first network card as Ports/Slaves. Didn't help.

I have rebooted VM and mainserver but that VM still does not have network ?

-----------------------------------------------------

Looking from Proxmox itself, both looks ok:

root@px-ve2:~# cat /etc/network/interfaces
# network interface settings; autogenerated
# Please do NOT modify this file directly, unless you know what
# you're doing.
#
# If you want to manage parts of the network configuration manually,
# please utilize the 'source' or 'source-directory' directives to do
# so.
# PVE will preserve these directives, but will NOT read its network
# configuration from sourced files, so do not attempt to move any of
# the PVE managed interfaces into external files!

source /etc/network/interfaces.d/*

auto lo
iface lo inet loopback

allow-hotplug enp4s0

iface enp4s0 inet manual

iface enp5s2 inet manual

auto vmbr0
iface vmbr0 inet static
address 84.XXX.XXX.129
netmask 255.255.255.0
gateway 84.XXX.XXX.254
bridge-ports enp4s0
bridge-stp off
bridge-fd 0

root@px-ve2:~#

-----------------------------------------------------

Attached image from VM im trying to get to network.

Any ideas ?

 

[Richard]

Possible that basic Debian installation ignores /etc/network/interfaces
Check configuration by

ip addr

 

[Kimmo H]

I attached image of node1 VM and node2 VM "ip addr" , looks same to me. Cluster Node1 (VM web4) has connection to internet but node2 (VM nagios) has not connection to internet.

Both physical servers are in same switch and network. VM is Ubuntu 18.04 LTS installed from same NFS-share .iso

 

[Richard]

Please precise what exactly the screenshot shows. My suggestion was to run

ip addr

in the two nodes (hosts) - but I guess at least one of them has been done in a VM.

 

[Kimmo H]

Ah sorry, here are "ip addr" of physical nodes, px-ve1 (which works) and px-ve2 (that VM's does not get to the router).

------------------------------------------------------------------------------------------------
root@px-ve1:~# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: enp3s0f0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq master vmbr0 state UP group default qlen 1000
link/ether ac:16:2d:a5:69:64 brd ff:ff:ff:ff:ff:ff
3: enp3s0f1: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
link/ether ac:16:2d:a5:69:66 brd ff:ff:ff:ff:ff:ff
4: enp4s0f0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
link/ether ac:16:2d:a5:69:04 brd ff:ff:ff:ff:ff:ff
5: enp4s0f1: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
link/ether ac:16:2d:a5:69:06 brd ff:ff:ff:ff:ff:ff
6: ens1: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
link/ether 00:02:c9:53:6a:54 brd ff:ff:ff:ff:ff:ff
7: vmbr0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
link/ether ac:16:2d:a5:69:64 brd ff:ff:ff:ff:ff:ff
inet 84.X.X.128/24 brd 84.X.X.255 scope global vmbr0
valid_lft forever preferred_lft forever
inet6 fe80::ae16:2dff:fea5:6964/64 scope link
valid_lft forever preferred_lft forever
8: tap100i0: <BROADCAST,MULTICAST,PROMISC,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master vmbr0 state UNKNOWN group default qlen 1000
link/ether 56:85:7b:5e:e1:f8 brd ff:ff:ff:ff:ff:ff
11: tap101i0: <BROADCAST,MULTICAST,PROMISC,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master vmbr0 state UNKNOWN group default qlen 1000
link/ether a2:f5:91:91:67:fe brd ff:ff:ff:ff:ff:ff
root@px-ve1:~#

------------------------------------------------------------------------------------------------

root@px-ve2:~# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: enp4s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq master vmbr0 state UP group default qlen 1000
link/ether 00:1a:a0:3c:20:29 brd ff:ff:ff:ff:ff:ff
3: enp5s2: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
link/ether 00:a0:24:4d:12:55 brd ff:ff:ff:ff:ff:ff
4: vmbr0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
link/ether 00:1a:a0:3c:20:29 brd ff:ff:ff:ff:ff:ff
inet 84.X.X.129/24 brd 84.X.X.255 scope global vmbr0
valid_lft forever preferred_lft forever
inet6 fe80::21a:a0ff:fe3c:2029/64 scope link
valid_lft forever preferred_lft forever
5: tap102i0: <BROADCAST,MULTICAST,PROMISC,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master vmbr0 state UNKNOWN group default qlen 1000
link/ether 7e:ec:af:55:8c:c2 brd ff:ff:ff:ff:ff:ff
root@px-ve2:~#

------------------------------------------------------------------------------------------------

 

[Richard]

Ah sorry, here are "ip addr" of physical nodes, px-ve1 (which works) and px-ve2 (that VM's does not get to the router).

Configuration looks good. In order to figure out what the problem is try to send packets from your VM to the requested destination and follow them step by step via tcpdump, e.g.

in the VM:

tcpdump -e -n -i ens18

in the Host:

tcpdump -e -n -i tap102i0
tcpdump -e -n -i vmbr0
tcpdump -e -n -i enp4s0

You will the see where the packets are not transported further.

If outgoing packets leave the system at enp4s0 correctly but there is no answer from outside, the problem is in the network and can be e.g.
- router settings not as expected
- VM's MAC address not accepted

 

[Scrummie02]

I did that and saw icmp packets but not leaving. turns out an iptables forward chain was set to deny. Not sure why that happened.

 

[Kimmo H]

I did that and saw icmp packets but not leaving. turns out an iptables forward chain was set to deny. Not sure why that happened.

Why are you answering to my questions which you don't have a clue? Are you bot ?

 

[t.lamprecht]

I did that and saw icmp packets but not leaving. turns out an iptables forward chain was set to deny. Not sure why that happened.

maybe you meant to post to your thread at: https://forum.proxmox.com/posts/246881/ ?