[SOLVED] no more network


New Member
Sep 27, 2019

Since last upgrade, I've got no network connection. I can't understand what is wrong. Here is some informations that could be useful :

cat /etc/network/interfaces

auto lo
iface lo inet loopback

allow-hotplug eno1

#iface eno1 inet dhcp
iface eno1 inet manual

iface eno2 inet manual

iface eno3 inet manual

iface eno4 inet manual

auto vmbr0
iface vmbr0 inet dhcp
    bridge_ports eno1
    bridge_stp off
    bridge_fd 0

With this file, network access was ok

dmesg | grep eno1
dmesg grep eno1_800.jpg

Without grep, I can see some red messages in dmseg, but I don't know if it's related to my network problems :


ip a
ip a_800.jpg

systemctl status networking.service
systemctl status networking.service_800.jpg

I've disabled ipv6 with echo net.ipv6.conf.all.disable_ipv6=1 > /etc/sysctl.d/disableipv6.conf but nothing change.

I've got some errors message at startup but I'm not sure that's the problem:

I'm too bad to understand what I can do. Please help me.


  • 20190927_100654_800.jpg
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You don't receive response from your DHCP server.
Your DHCP server is on the same network ?
Is it a FAI box or a Linux DHCP server ? (You can make a tcpdump ?)
When you set a fixed IP you can ping gateway ?

Is not recommended to use a dynamic IP :)

To snif network, you can use this command on your personnal computer, server and DHCP server :
tcpdump -i br0 -vvv -s 1500 '((port 67 or port 68) and (udp[8:1] = 0x1))'
(DHCP DISCOVER is broadcasted so everything receive DHCP request.

Thank you for this answer.

It's not a dynamic IP, DHCP is used to assign IP from mac address with gestip. DHCP server communicated well with the machine before the upgrade
under iface vmbr0 inet dhcp I add hwaddress ether 01:23:45:67:89:0a and… it solved !


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