Meet an new issues about creating dns cleanup

Hi , i run the tailscale in arm ubuntu 18.04 .
But failed with

Jan 29 03:40:45 localhost.localdomain tailscaled[15999]: logtail started
Jan 29 03:40:45 localhost.localdomain tailscaled[15999]: Program starting: v1.18.2-tcc23fba40-ge21a681f4, Go 1.17.2-ts7037d3ea51: []string{"/usr/sbin/tailscaled", "--cleanup"}
Jan 29 03:40:45 localhost.localdomain tailscaled[15999]: LogID: 38e5e6e5f9a0de32ce54654f4efb4cc9d268ad78fa5cbc236aea5ac03fbd1dd4
Jan 29 03:40:45 localhost.localdomain tailscaled[15999]: logpolicy: using system state directory "/var/lib/tailscale"
Jan 29 03:40:45 localhost.localdomain tailscaled[15999]: dns: [rc=resolved nm=yes nm-resolved=yes nm-safe=no ret=systemd-resolved]
Jan 29 03:40:45 localhost.localdomain tailscaled[15999]: creating dns cleanup: route ip+net: no such network interface
Jan 29 03:40:45 localhost.localdomain tailscaled[15999]: flushing log.
Jan 29 03:40:45 localhost.localdomain tailscaled[15999]: logger closing down
Jan 29 03:40:46 localhost.localdomain tailscaled[15999]: logtail: dialed "log.tailscale.io:443" in 217ms
Jan 29 03:40:46 localhost.localdomain tailscaled[16006]: logtail started
Jan 29 03:40:46 localhost.localdomain tailscaled[16006]: Program starting: v1.18.2-tcc23fba40-ge21a681f4, Go 1.17.2-ts7037d3ea51: []string{"/usr/sbin/tailscaled", "--state=/var/li
Jan 29 03:40:46 localhost.localdomain tailscaled[16006]: LogID: 38e5e6e5f9a0de32ce54654f4efb4cc9d268ad78fa5cbc236aea5ac03fbd1dd4
Jan 29 03:40:46 localhost.localdomain tailscaled[16006]: logpolicy: using system state directory "/var/lib/tailscale"
Jan 29 03:40:46 localhost.localdomain tailscaled[16006]: wgengine.NewUserspaceEngine(tun "tailscale0") ...
Jan 29 03:40:46 localhost.localdomain tailscaled[16006]: Linux kernel version: 4.19.206
Jan 29 03:40:46 localhost.localdomain tailscaled[16006]: is CONFIG_TUN enabled in your kernel? `modprobe tun` failed with: modprobe: FATAL: Module tun not found in directory /lib/
Jan 29 03:40:46 localhost.localdomain tailscaled[16006]: tun module not loaded nor found on disk
Jan 29 03:40:46 localhost.localdomain tailscaled[16006]: wgengine.NewUserspaceEngine(tun "tailscale0") error: tstun.New("tailscale0"): CreateTUN("tailscale0") failed; /dev/net/tun
Jan 29 03:40:46 localhost.localdomain tailscaled[16006]: wgengine.New: tstun.New("tailscale0"): CreateTUN("tailscale0") failed; /dev/net/tun does not exist
Jan 29 03:40:46 localhost.localdomain tailscaled[16006]: flushing log.
Jan 29 03:40:46 localhost.localdomain tailscaled[16006]: logger closing down
Jan 29 03:40:46 localhost.localdomain tailscaled[16006]: logtail: dialed "log.tailscale.io:443" in 223ms
Jan 29 03:40:47 localhost.localdomain systemd[1]: tailscaled.service: Main process exited, code=exited, status=1/FAILURE
Jan 29 03:40:47 localhost.localdomain tailscaled[16015]: logtail started
Jan 29 03:40:47 localhost.localdomain tailscaled[16015]: Program starting: v1.18.2-tcc23fba40-ge21a681f4, Go 1.17.2-ts7037d3ea51: []string{"/usr/sbin/tailscaled", "--cleanup"}
Jan 29 03:40:47 localhost.localdomain tailscaled[16015]: LogID: 38e5e6e5f9a0de32ce54654f4efb4cc9d268ad78fa5cbc236aea5ac03fbd1dd4
Jan 29 03:40:47 localhost.localdomain tailscaled[16015]: logpolicy: using system state directory "/var/lib/tailscale"
Jan 29 03:40:47 localhost.localdomain tailscaled[16015]: dns: [rc=resolved nm=yes nm-resolved=yes nm-safe=no ret=systemd-resolved]
Jan 29 03:40:47 localhost.localdomain tailscaled[16015]: creating dns cleanup: route ip+net: no such network interface
Jan 29 03:40:47 localhost.localdomain tailscaled[16015]: flushing log.
Jan 29 03:40:47 localhost.localdomain tailscaled[16015]: logger closing down
Jan 29 03:40:47 localhost.localdomain tailscaled[16015]: logtail: dialed "log.tailscale.io:443" in 217ms

And seem like it have some problem with action creating dns cleanup , it have been try for 2 version both 1.20.0 and 1.18.2

Jan 29 03:40:46 localhost.localdomain tailscaled[16006]: wgengine.New: tstun.New(“tailscale0”): CreateTUN(“tailscale0”) failed; /dev/net/tun does not exist

This is the main problem. If this is a container, you may need to export /dev/net/tun from the host: Tailscale in LXC containers · Tailscale

If this is a standalone system or VM, try: modprobe tun

1 Like

Sry , but i do directly run it in the System (Ubuntu 18.04 - Arm)
And … how can i solve it ? need to open some port ? or config the network interface?
Thanks !!!

Is this a hardware ARM system, a VM, or a container?

If it is a hardware ARM system, try running as root: modprobe tun

Yes , hardware ARM , and i found it have no tun with this linux core . Thanks .
So it will work with i build an new core with tun , right ? Thanks !

This is the error to solve. You need a /dev/net/tun device.