TUN0 device no present after reboot

[sebr]

Hello,
I flashed a TP Ling MR-6400 router to have OpenVPN as a client.
I manage to connect to the VPN well and I managed to get the connection to work, but with great difficulty.
But now after a restart I lose the TUN0 connection the interface is no longer detected.

I disconnected / reconnected the VPN and restarted the TUN0 interface but could not get the interface to reconnect.
I deleted and put back the interface it is connected but no connection and if I restart the router I lose the interface again.
I followed what is in this subject at the level of the config file and the .config everything is OK on this side.

Tun0 - Error: Network device is not present

Ok, thanks for making me aware guys. That was a n00b move on my part. I executed the following command [CL] Which in turn made the "Network device is not present" not there anymore ... [ND] And the system log now shows [SL] What command line can I execute to start the openvpn manually ?

I don't really see what to do to get my connection to the VPN working again.
I see attached logs.
Thank you for your help.

root@OpenWrt:~# uci show network; uci show firewall; uci show dhcp; uci show ope
nvpn
network.loopback=interface
network.loopback.device='lo'
network.loopback.proto='static'
network.loopback.ipaddr='127.0.0.1'
network.loopback.netmask='255.0.0.0'
network.globals=globals
network.globals.ula_prefix='fd48:253f:ec2c::/48'
network.@device[0]=device
network.@device[0].name='br-lan'
network.@device[0].type='bridge'
network.@device[0].ports='eth0.1'
network.lan=interface
network.lan.device='br-lan'
network.lan.proto='static'
network.lan.netmask='255.255.255.0'
network.lan.ip6assign='60'
network.lan.ipaddr='192.168.2.1'
network.wan=interface
network.wan.device='usb0'
network.wan.proto='dhcp'
network.wan6=interface
network.wan6.device='usb0'
network.wan6.proto='dhcpv6'
network.@switch[0]=switch
network.@switch[0].name='switch0'
network.@switch[0].reset='1'
network.@switch[0].enable_vlan='1'
network.@switch_vlan[0]=switch_vlan
network.@switch_vlan[0].device='switch0'
network.@switch_vlan[0].vlan='1'
network.@switch_vlan[0].ports='1 2 3 0t'
network.WANNET=interface
network.WANNET.proto='static'
network.WANNET.device='eth1'
network.WANNET.ipaddr='192.168.1.250'
network.WANNET.netmask='255.255.255.0'
network.WANNET.gateway='192.168.1.1'
network.WANNET.broadcast='192.168.1.255'
network.WANNET.dns='8.8.8.8'
network.TUN0=interface
network.TUN0.proto='none'
network.TUN0.device='tun0'
firewall.@defaults[0]=defaults
firewall.@defaults[0].syn_flood='1'
firewall.@defaults[0].input='ACCEPT'
firewall.@defaults[0].output='ACCEPT'
firewall.@defaults[0].forward='REJECT'
firewall.@zone[0]=zone
firewall.@zone[0].name='lan'
firewall.@zone[0].input='ACCEPT'
firewall.@zone[0].output='ACCEPT'
firewall.@zone[0].forward='ACCEPT'
firewall.@zone[0].network='lan'
firewall.@zone[1]=zone
firewall.@zone[1].name='wan'
firewall.@zone[1].input='REJECT'
firewall.@zone[1].output='ACCEPT'
firewall.@zone[1].forward='REJECT'
firewall.@zone[1].masq='1'
firewall.@zone[1].mtu_fix='1'
firewall.@zone[1].network='wan' 'wan6' 'WANNET' 'TUN0'
firewall.@forwarding[0]=forwarding
firewall.@forwarding[0].src='lan'
firewall.@forwarding[0].dest='wan'
firewall.@rule[0]=rule
firewall.@rule[0].name='Allow-DHCP-Renew'
firewall.@rule[0].src='wan'
firewall.@rule[0].proto='udp'
firewall.@rule[0].dest_port='68'
firewall.@rule[0].target='ACCEPT'
firewall.@rule[0].family='ipv4'
firewall.@rule[1]=rule
firewall.@rule[1].name='Allow-Ping'
firewall.@rule[1].src='wan'
firewall.@rule[1].proto='icmp'
firewall.@rule[1].icmp_type='echo-request'
firewall.@rule[1].family='ipv4'
firewall.@rule[1].target='ACCEPT'
firewall.@rule[2]=rule
firewall.@rule[2].name='Allow-IGMP'
firewall.@rule[2].src='wan'
firewall.@rule[2].proto='igmp'
firewall.@rule[2].family='ipv4'
firewall.@rule[2].target='ACCEPT'
firewall.@rule[3]=rule
firewall.@rule[3].name='Allow-DHCPv6'
firewall.@rule[3].src='wan'
firewall.@rule[3].proto='udp'
firewall.@rule[3].dest_port='546'
firewall.@rule[3].family='ipv6'
firewall.@rule[3].target='ACCEPT'
firewall.@rule[4]=rule
firewall.@rule[4].name='Allow-MLD'
firewall.@rule[4].src='wan'
firewall.@rule[4].proto='icmp'
firewall.@rule[4].src_ip='fe80::/10'
firewall.@rule[4].icmp_type='130/0' '131/0' '132/0' '143/0'
firewall.@rule[4].family='ipv6'
firewall.@rule[4].target='ACCEPT'
firewall.@rule[5]=rule
firewall.@rule[5].name='Allow-ICMPv6-Input'
firewall.@rule[5].src='wan'
firewall.@rule[5].proto='icmp'
firewall.@rule[5].icmp_type='echo-request' 'echo-reply' 'destination-unreachable' 'packet-too-big' 'time-exceeded' 'bad-header' 'unknown-header-type' 'router-solicitation' 'neighbour-solicitation' 'router-advertisement' 'neighbour-advertisement'
firewall.@rule[5].limit='1000/sec'
firewall.@rule[5].family='ipv6'
firewall.@rule[5].target='ACCEPT'
firewall.@rule[6]=rule
firewall.@rule[6].name='Allow-ICMPv6-Forward'
firewall.@rule[6].src='wan'
firewall.@rule[6].dest='*'
firewall.@rule[6].proto='icmp'
firewall.@rule[6].icmp_type='echo-request' 'echo-reply' 'destination-unreachable' 'packet-too-big' 'time-exceeded' 'bad-header' 'unknown-header-type'
firewall.@rule[6].limit='1000/sec'
firewall.@rule[6].family='ipv6'
firewall.@rule[6].target='ACCEPT'
firewall.@rule[7]=rule
firewall.@rule[7].name='Allow-IPSec-ESP'
firewall.@rule[7].src='wan'
firewall.@rule[7].dest='lan'
firewall.@rule[7].proto='esp'
firewall.@rule[7].target='ACCEPT'
firewall.@rule[8]=rule
firewall.@rule[8].name='Allow-ISAKMP'
firewall.@rule[8].src='wan'
firewall.@rule[8].dest='lan'
firewall.@rule[8].dest_port='500'
firewall.@rule[8].proto='udp'
firewall.@rule[8].target='ACCEPT'
dhcp.@dnsmasq[0]=dnsmasq
dhcp.@dnsmasq[0].domainneeded='1'
dhcp.@dnsmasq[0].boguspriv='1'
dhcp.@dnsmasq[0].filterwin2k='0'
dhcp.@dnsmasq[0].localise_queries='1'
dhcp.@dnsmasq[0].rebind_protection='1'
dhcp.@dnsmasq[0].rebind_localhost='1'
dhcp.@dnsmasq[0].local='/lan/'
dhcp.@dnsmasq[0].domain='lan'
dhcp.@dnsmasq[0].expandhosts='1'
dhcp.@dnsmasq[0].nonegcache='0'
dhcp.@dnsmasq[0].authoritative='1'
dhcp.@dnsmasq[0].readethers='1'
dhcp.@dnsmasq[0].leasefile='/tmp/dhcp.leases'
dhcp.@dnsmasq[0].resolvfile='/tmp/resolv.conf.d/resolv.conf.auto'
dhcp.@dnsmasq[0].nonwildcard='1'
dhcp.@dnsmasq[0].localservice='1'
dhcp.@dnsmasq[0].ednspacket_max='1232'
dhcp.lan=dhcp
dhcp.lan.interface='lan'
dhcp.lan.start='100'
dhcp.lan.limit='150'
dhcp.lan.leasetime='12h'
dhcp.lan.dhcpv4='server'
dhcp.lan.dhcpv6='server'
dhcp.lan.ra='server'
dhcp.lan.ra_flags='managed-config' 'other-config'
dhcp.wan=dhcp
dhcp.wan.interface='wan'
dhcp.wan.ignore='1'
dhcp.odhcpd=odhcpd
dhcp.odhcpd.maindhcp='0'
dhcp.odhcpd.leasefile='/tmp/hosts/odhcpd'
dhcp.odhcpd.leasetrigger='/usr/sbin/odhcpd-update'
dhcp.odhcpd.loglevel='4'
openvpn.custom_config=openvpn
openvpn.custom_config.config='/etc/openvpn/my-vpn.conf'
openvpn.sample_server=openvpn
openvpn.sample_server.port='1194'
openvpn.sample_server.proto='udp'
openvpn.sample_server.dev='tun'
openvpn.sample_server.ca='/etc/openvpn/ca.crt'
openvpn.sample_server.cert='/etc/openvpn/server.crt'
openvpn.sample_server.key='/etc/openvpn/server.key'
openvpn.sample_server.dh='/etc/openvpn/dh2048.pem'
openvpn.sample_server.server='10.8.0.0 255.255.255.0'
openvpn.sample_server.ifconfig_pool_persist='/tmp/ipp.txt'
openvpn.sample_server.keepalive='10 120'
openvpn.sample_server.persist_key='1'
openvpn.sample_server.persist_tun='1'
openvpn.sample_server.user='nobody'
openvpn.sample_server.status='/tmp/openvpn-status.log'
openvpn.sample_server.verb='3'
openvpn.sample_client=openvpn
openvpn.sample_client.client='1'
openvpn.sample_client.dev='tun'
openvpn.sample_client.proto='udp'
openvpn.sample_client.remote='my_server_1 1194'
openvpn.sample_client.resolv_retry='infinite'
openvpn.sample_client.nobind='1'
openvpn.sample_client.persist_key='1'
openvpn.sample_client.persist_tun='1'
openvpn.sample_client.user='nobody'
openvpn.sample_client.ca='/etc/openvpn/ca.crt'
openvpn.sample_client.cert='/etc/openvpn/client.crt'
openvpn.sample_client.key='/etc/openvpn/client.key'
openvpn.sample_client.verb='3'
openvpn.cpbvrc=openvpn
openvpn.cpbvrc.config='/etc/openvpn/cpbvrc.ovpn'
openvpn.cpbvrc.enabled='1'

[ulmwind]

/etc/init.d/openvpn enable

[mk24]

The tun0 interface is created, started and managed by the OpenVPN client program. Running /etc/init.d/openvpn restart should restart the connection and bring up tun0. If it does not, check the log for errors reported by OpenVPN.

What @ulmwind said, the enable command will enable OpenVPN to be started at boot. That does not also immediately start it though, for that use start or restart.

[sebr]

Thank you for your answers.
I had deleted the tun0 interface, I redid it, everything was connected, even my vpn, but I always go to the IP of my house and not of my VPN server.
So I did a reboot which reproduced the error, I gave the command /etc/init.d/openvpn restart I still have Network device is not present.
Where are the OpenVPN logs?
Thanks

[mk24]

In the system log.
Also check the routing table to confirm that route all Internet through VPN has been set up.

[sebr]

I disabled the VPN I did something else, I put the PC back the card became and I go through the VPN again. It's not to understand anything because sometimes it works and sometimes I have trouble putting the Tun0 back on or once it's good nothing goes through the VPN.

If it works is that everything is well configured so that all internet goes through the VPN?
At firewall level I added tun0

[ulmwind]

It is recommended to create additional zone for tun adapter.

See logs:

logread
logread -e openvpn

[mk24]

@ulmwind

It is recommended to create additional zone for tun adapter.

Yes and also within the firewall config you should use list device tun0 instead of the old way of creating a proto none network in /etc/config/network. The only reason for the old method was to associate an interface name with a device name.

Again it is important to remember that the OpenVPN program is expected to totally control the tun0 device. Do not attempt to create, reconfigure or remove it outside of OpenVPN.

[sebr]

Thank you for your answers I will try this even if I did not understand everything in mk24's message but I will try.