Lost net connection with server

Pitmaster · April 6, 2018, 7:18pm

NethServer Version: 7.4
Module: general

Hi all, I had a good server but I wanted to make WebVirtmgr working and made an extra NIC.
Connection lost!
Now I plugged in a monitor and removed all the NIC’s and started all over again (network).

I still can’t connect, not even ping to the server. I did even stopt shorewall service. (If that’s the only thing to stop to stop firewall).

Help me here plz? Thanks, Pit

dnutan · April 6, 2018, 8:49pm

What’s the output of db networks show ?
Did you follow the steps on the manual to Reset Network Configuration?

Another option could be to bring the network interface up and use dhclient command to get assigned a new IP address by DHCP.

Pitmaster · April 7, 2018, 8:19am

I did indeed exactly those steps yes.
After that the signal-event system-init I had a basic set of NIC’s.

I rebooted, after that two virt NIC’s where added.
Now I have 5 NIC’s, lo, br0, br1, virtbr0 and virtbr1.
br0 192.168.0.134 and br1 192.168.0.136

Pit

dnutan · April 7, 2018, 10:50am

You can try to disable autostart of the network(s) created by webvirtmgr using virsh command:

virsh
net-list
net-autostart networkname --disable
exit

Then reboot the server and check if virt* interfaces are not shown with ifconfig or ip a commands, and if you regained access to the server.

Another option is to remove the active network(s) created by webvirtmgr:

virsh
net-list
net-destroy networkname
net-undefine networkname
exit

Then restart libvirt:

systemctl restart libvirtd

Can you describe your network layout? Why are both interfaces within the same network range? Output of db networks show could be useful too.

Pitmaster · April 8, 2018, 8:16am

First output of db networks show
br0=bridge
gateway=192.168.0.1
ipaddr=192.168.0.134
netmask=255.255.255.0
role=green
br1=bridge
bootproto=none
gateway=192.168.0.1
ipaddr=192.168.0.136
netmask=255.255.255.0
role=green
enp0s31f6=ethernet
FwInBandwidth=
FwOutBandwidth=
bootproto=none
bridge=br1
role=bridged
ppp0=xdsl-disabled
AuthType=auto
FwInBandwidth=
FwOutBandwidth=
Password=
name=PPPoE
provider=xDSL provider
role=red
user=

virsh net-list gave me default and eth0
It was the first time I see my old eth0 back, I am used to see that name on ubuntu.

The description of my network?
Easy, I have a fyber connection 512 mbit, to a router, the router give dhcp.
And thats it. All the system get there ip address from that router or I give them a static.
Both br0 and br1 have static ip.
The server has an AD DS and WebVirtMgr running. Also httpd etc…

Pit

dnutan · April 9, 2018, 8:13pm

In Red Hat Enterprise Linux 7 [thus same in CentOS 7 and NethServer 7], udev supports a number of different naming schemes. The default is to assign fixed names based on firmware, topology, and location information. This has the advantage that the names are fully automatic, fully predictable, that they stay fixed even if hardware is added or removed (no re-enumeration takes place), and that broken hardware can be replaced seamlessly. The disadvantage is that they are sometimes harder to read than the eth0 or wlan0 names traditionally used. For example: enp5s0.

Source

Can you ping any of the two IP addresses or, if httpd-admin service is running, access the server-manager using any of them? (If I recall correctly you use a custom port number for the server-manager, verify it didn’t change).
If not working, you could try to remove one of the bridges:

Identify the bridge used by AD (example: br0):

config show nsdc

Delete the other bridge (example uses br1):

db networks delete br1
ifconfig br1 down
brctl delbr br1
rm -f /etc/sysconfig/network-scripts/ifcfg-br1
service network restart
signal-event system-init

/var/log/messages might give some clues on the problem.

Pitmaster · April 10, 2018, 11:30am

@Marc, thx.
No, i can’t ping the NIC’s. The portnumber isn’t changed.
I still can’t ping the address left.

Pit
thinking of reinstall the whole thing.

dnutan · April 10, 2018, 11:36am

@support_team , any advice for Nico before going for a reinstall?

mrmarkuz · April 10, 2018, 11:56am

Did you configure your Nethserver via web UI between reset and reboot? I’d give the network reset another try before reinstalling…

Maybe just try with only one (green) interface…

My network config when having AD and webvirtmgr installed, just to compare:

# db networks show
br0=bridge
    FwInBandwidth=
    FwOutBandwidth=
    bootproto=none
    gateway=
    ipaddr=192.168.1.1
    netmask=255.255.255.0
    role=green
ens192=ethernet
    FwInBandwidth=
    FwOutBandwidth=
    bridge=br0
    role=bridged
ens224=ethernet
    FwInBandwidth=
    FwOutBandwidth=
    bootproto=none
    gateway=192.168.0.1
    ipaddr=192.168.0.2
    netmask=255.255.255.0
    role=red
ppp0=xdsl-disabled
    AuthType=auto
    FwInBandwidth=
    FwOutBandwidth=
    Password=
    name=PPPoE
    provider=xDSL provider
    role=red
    user=
red1=provider
    interface=ens224
    weight=1

Pitmaster · April 10, 2018, 12:29pm

I did the whole thing on console. I can’t reach WebIU.

Pit

Pitmaster · April 10, 2018, 12:50pm

Now the situation is as follow:

db networks show
enp0s31f6=ethernet
FwInBandwidth=
FwOutBandwidth=
bootproto=none
bridge=br1
role=bridged
ppp0=xdsl-disabled
AuthType=auto
FwInBandwidth=
FwOutBandwidth=
Password=
name=PPPoE
provider=xDSL provider
role=red
user=

ifconfig
enp0s31f6: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.0.134 netmask 255.255.255.0 broadcast 192.168.0.255
inet6 fe80::1e1b:dff:fe97:e4dc prefixlen 64 scopeid 0x20
ether 1c:1b:0d:97:e4:dc txqueuelen 1000 (Ethernet)
RX packets 776469 bytes 202230191 (192.8 MiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 56 bytes 4592 (4.4 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
device interrupt 16 memory 0x92f00000-92f20000

lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10
loop txqueuelen 1 (Local Loopback)
RX packets 79873 bytes 5065352 (4.8 MiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 79873 bytes 5065352 (4.8 MiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

ping from near station
PING 192.168.0.134 (192.168.0.134) 56(84) bytes of data.
From 192.168.0.123 icmp_seq=1 Destination Host Unreachable
From 192.168.0.123 icmp_seq=2 Destination Host Unreachable
From 192.168.0.123 icmp_seq=3 Destination Host Unreachable
From 192.168.0.123 icmp_seq=4 Destination Host Unreachable
From 192.168.0.123 icmp_seq=5 Destination Host Unreachable
From 192.168.0.123 icmp_seq=6 Destination Host Unreachable
From 192.168.0.123 icmp_seq=7 Destination Host Unreachable
From 192.168.0.123 icmp_seq=8 Destination Host Unreachable
From 192.168.0.123 icmp_seq=9 Destination Host Unreachable
From 192.168.0.123 icmp_seq=10 Destination Host Unreachable
From 192.168.0.123 icmp_seq=11 Destination Host Unreachable
From 192.168.0.123 icmp_seq=12 Destination Host Unreachable
From 192.168.0.123 icmp_seq=13 Destination Host Unreachable

So, I think it is time to reinstall, isn’t?

Pit

Pitmaster · April 10, 2018, 12:52pm

A problem is, the machine is here at home, after full configuration i have to take it to my classroom where i teach. The network sistuation there is totally different so i maybe have the same problems all over again.

Pit

Pitmaster · April 10, 2018, 12:53pm

Guess my teaching skills

Pit

it’s not english

mrmarkuz · April 10, 2018, 1:16pm

When reinstalling I recommend to start with setup local AD because it configures the bridge you may just use in webvirtmgr.

https://wiki.nethserver.org/doku.php?id=userguide:how_to_configure_and_run_a_vm_with_webvirtmgr_on_nethserver

Maths?

You may just setup the Nethserver at home. Then configure a network client (laptop, school pc) to be in your home network by giving it an IP like 192.168.0.222 so you may reach the web UI of Nethserver with that client at school and then being able to configure your Nethserver to work in the school network.

Don’t forget to change IP of the AD container at school too:
http://docs.nethserver.org/en/v7/accounts.html#samba-active-directory-local-provider-installation

Pitmaster · April 10, 2018, 1:29pm

IT, specialy Linux

Thx for the info. I worked meanly with Debian likes.

Pit

Pitmaster · April 10, 2018, 1:36pm

I think I am going to try and use VirtualBox in the next version of this server.

Pit

mrmarkuz · April 10, 2018, 1:48pm

Good idea, it’s easier to test things in a VM.

There are some Nethserver school/education projects you may have a look at:

flatspin · April 10, 2018, 3:07pm

Maybe you could try to configure your interface manually:

    db networks set br0 bridge
    db networks setprop br0 ipaddr 192.168.0.134
    db networks setprop br0 netmask 255.255.255.0
    db networks setprop br0 gateway 192.168.0.1
    db networks setprop br0 role green

    db networks delete enps31f6
    db networks set eth0 ethernet
    db networks setprop eth0 bridge br0
    db networks setprop eth0 role bridged

db networks show => output should look similar to @mrmarkuz post

signal-event interface-update

Maybe you have to reboot. Important is “role=green” to be reachable.

Pitmaster · April 10, 2018, 3:37pm

I have allready reinstalled the system. Started all over again.
Everything is working fine now.
I want to thank Markus for his great post, I think I will use a lot from that page. Thanks!

Pit

flatspin · April 10, 2018, 3:50pm

Great to hear everything is working again.
Please mark the topic as solved then.

Have a great time with Nethserver!