NetworkManager is not changing /etc/resolv.conf after openvpn dns push
I've got a problem which is "NetworkManager is not updating /etc/resolv.conf after openvpn connection with dns push configured".
Here's my openvpn server config: (I've changed domain name to ABC.COM for security reason ;))
########################################
# Sample OpenVPN config file for
# 2.0-style multi-client udp server
#
# Adapted from http://openvpn.sourceforge.net/20notes.html
#
# tun-style tunnel
port 1194
dev tun
# Use "local" to set the source address on multi-homed hosts
#local [IP address]
# TLS parms
tls-server
ca keys/ca.crt
cert keys/static.crt
key keys/static.key
dh keys/dh1024.pem
proto tcp-server
# Tell OpenVPN to be a multi-client udp server
mode server
# The server's virtual endpoints
ifconfig 10.8.0.1 10.8.0.2
# Pool of /30 subnets to be allocated to clients.
# When a client connects, an --ifconfig command
# will be automatically generated and pushed back to
# the client.
ifconfig-pool 10.8.0.4 10.8.0.255
# Push route to client to bind it to our local
# virtual endpoint.
push "route 10.8.0.1 255.255.255.255"
push "dhcp-option DNS 10.8.0.1"
# Push any routes the client needs to get in
# to the local network.
#push "route 192.168.0.0 255.255.255.0"
# Push DHCP options to Windows clients.
push "dhcp-option DOMAIN ABC.COM"
#push "dhcp-option DNS 192.168.0.1"
#push "dhcp-option WINS 192.168.0.1"
# Client should attempt reconnection on link
# failure.
keepalive 10 60
# Delete client instances after some period
# of inactivity.
inactive 600
# Route the --ifconfig pool range into the
# OpenVPN server.
route 10.8.0.0 255.255.255.0
# The server doesn't need privileges
user openvpn
group openvpn
# Keep TUN devices and keys open across restarts.
persist-tun
persist-key
verb 4
As you can see it's basicaly sample config with little tuning.
Now..
On my machine (openvpn client), I can see that dns is ok:
{17:12}/etc/NetworkManager ➭ nslookup git.ABC.COM 10.8.0.1
Server: 10.8.0.1
Address: 10.8.0.1#53
Name: git.ABC.COM
Address: 10.8.0.1
{17:18}/etc/NetworkManager ➭ nslookup ABC.COM 10.8.0.1
Server: 10.8.0.1
Address: 10.8.0.1#53
Name: ABC.COM
Address: 18X.XX.XX.71
openvpn logs on server side says (if I understand correctly) that DNS has been pushed:
openvpn[13257]: TCPv4_SERVER link remote: [AF_INET]83.30.135.214:37658
openvpn[13257]: 83.30.135.214:37658 TLS: Initial packet from [AF_INET]83.30.135.214:37658, sid=3251df51 915772f3
openvpn[13257]: 83.30.135.214:37658 VERIFY OK: depth=1, C=XX, ST=XX, L=XXX, O=XXX, OU=XXX, CN=XXX, name=XXX, [email protected]
openvpn[13257]: 83.30.135.214:37658 VERIFY OK: depth=0, C=XX, ST=XX, L=XXX, O=XXX, OU=XXX, CN=XXX, name=XXX, [email protected]
openvpn[13257]: 83.30.135.214:37658 Data Channel Encrypt: Cipher 'BF-CBC' initialized with 128 bit key
openvpn[13257]: 83.30.135.214:37658 Data Channel Encrypt: Using 160 bit message hash 'SHA1' for HMAC authentication
openvpn[13257]: 83.30.135.214:37658 Data Channel Decrypt: Cipher 'BF-CBC' initialized with 128 bit key
openvpn[13257]: 83.30.135.214:37658 Data Channel Decrypt: Using 160 bit message hash 'SHA1' for HMAC authentication
openvpn[13257]: 83.30.135.214:37658 Control Channel: TLSv1, cipher TLSv1/SSLv3 DHE-RSA-AES256-SHA, 1024 bit RSA
openvpn[13257]: 83.30.135.214:37658 [jacek] Peer Connection Initiated with [AF_INET]83.30.135.214:37658
openvpn[13257]: jacek/83.30.135.214:37658 MULTI_sva: pool returned IPv4=10.8.0.10, IPv6=(Not enabled)
openvpn[13257]: jacek/83.30.135.214:37658 MULTI: Learn: 10.8.0.10 -> jacek/83.30.135.214:37658
openvpn[13257]: jacek/83.30.135.214:37658 MULTI: primary virtual IP for jacek/83.30.135.214:37658: 10.8.0.10
openvpn[13257]: jacek/83.30.135.214:37658 PUSH: Received control message: 'PUSH_REQUEST'
openvpn[13257]: jacek/83.30.135.214:37658 send_push_reply(): safe_cap=940
openvpn[13257]: jacek/83.30.135.214:37658 SENT CONTROL [jacek]: 'PUSH_REPLY,route 10.8.0.1 255.255.255.255,dhcp-option DNS 10.8.0.1,dhcp-option DOMAIN ABC.COM,ping 10,ping-restart 60,ifconfig 10.8.0.10 10.8.0.9' (status=1)
openvp logs on my side:
Aug 05 17:13:55 localhost.localdomain openvpn[1198]: TCPv4_CLIENT link remote: [AF_INET]XXX.XX.37.71:1194
Aug 05 17:13:55 localhost.localdomain openvpn[1198]: TLS: Initial packet from [AF_INET]XXX.XX.37.71:1194, sid=89cc981c d57dd826
Aug 05 17:13:56 localhost.localdomain openvpn[1198]: VERIFY OK: depth=1, C=XX, ST=XX, L=XXX, O=XXX, OU=XXX, CN=XXX, name=XXX, [email protected]
Aug 05 17:13:56 localhost.localdomain openvpn[1198]: VERIFY OK: depth=0, C=XX, ST=XX, L=XXX, O=XXX, OU=XXX, CN=XXX, name=XXX, [email protected]
Aug 05 17:13:58 localhost.localdomain openvpn[1198]: Data Channel Encrypt: Cipher 'BF-CBC' initialized with 128 bit key
Aug 05 17:13:58 localhost.localdomain openvpn[1198]: Data Channel Encrypt: Using 160 bit message hash 'SHA1' for HMAC authentication
Aug 05 17:13:58 localhost.localdomain openvpn[1198]: Data Channel Decrypt: Cipher 'BF-CBC' initialized with 128 bit key
Aug 05 17:13:58 localhost.localdomain openvpn[1198]: Data Channel Decrypt: Using 160 bit message hash 'SHA1' for HMAC authentication
Aug 05 17:13:58 localhost.localdomain openvpn[1198]: Control Channel: TLSv1, cipher TLSv1/SSLv3 DHE-RSA-AES256-SHA, 1024 bit RSA
Aug 05 17:13:58 localhost.localdomain openvpn[1198]: [static] Peer Connection Initiated with [AF_INET]XXX.XX.37.71:1194
Aug 05 17:14:00 localhost.localdomain openvpn[1198]: SENT CONTROL [static]: 'PUSH_REQUEST' (status=1)
Aug 05 17:14:01 localhost.localdomain openvpn[1198]: PUSH: Received control message: 'PUSH_REPLY,route 10.8.0.1 255.255.255.255,dhcp-option DNS 10.8.0.1,dhcp-option DOMAIN ABC.COM,ping 10,ping-restart 60,ifconfig 10.8.0.10 10.8.0.9'
Aug 05 17:14:01 localhost.localdomain openvpn[1198]: OPTIONS IMPORT: timers and/or timeouts modified
Aug 05 17:14:01 localhost.localdomain openvpn[1198]: OPTIONS IMPORT: --ifconfig/up options modified
Aug 05 17:14:01 localhost.localdomain openvpn[1198]: OPTIONS IMPORT: route options modified
Aug 05 17:14:01 localhost.localdomain openvpn[1198]: OPTIONS IMPORT: --ip-win32 and/or --dhcp-option options modified
Aug 05 17:14:01 localhost.localdomain openvpn[1198]: ROUTE_GATEWAY 10.123.123.1/255.255.255.0 IFACE=wlan0 HWADDR=44:6d:57:32:81:2e
Aug 05 17:14:01 localhost.localdomain openvpn[1198]: TUN/TAP device tun0 opened
Aug 05 17:14:01 localhost.localdomain openvpn[1198]: TUN/TAP TX queue length set to 100
Aug 05 17:14:01 localhost.localdomain openvpn[1198]: do_ifconfig, tt->ipv6=0, tt->did_ifconfig_ipv6_setup=0
Aug 05 17:14:01 localhost.localdomain openvpn[1198]: /usr/sbin/ip link set dev tun0 up mtu 1500
Aug 05 17:14:01 localhost.localdomain openvpn[1198]: /usr/sbin/ip addr add dev tun0 local 10.8.0.10 peer 10.8.0.9
Aug 05 17:14:01 localhost.localdomain openvpn[1198]: /usr/sbin/ip route add 10.8.0.1/32 via 10.8.0.9
Aug 05 17:14:01 localhost.localdomain openvpn[1198]: Initialization Sequence Completed
It looks like everything's fine.
But. I checked /var/log/messages also... and I found that line:
Aug 5 17:14:01 localhost NetworkManager[761]: <warn> /sys/devices/virtual/net/tun0: couldn't determine device driver; ignoring...
ip a returns:
5: tun0: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 100
link/none
inet 10.8.0.10 peer 10.8.0.9/32 scope global tun0
valid_lft forever preferred_lft forever
route -n returns:
# route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
0.0.0.0 10.123.123.1 0.0.0.0 UG 0 0 0 wlan0
10.8.0.1 10.8.0.9 255.255.255.255 UGH 0 0 0 tun0
10.8.0.9 0.0.0.0 255.255.255.255 UH 0 0 0 tun0
10.123.123.0 0.0.0.0 255.255.255.0 U 0 0 0 wlan0
So basically everything works, except the DNS being pushed... Oh! Right, and my /etc/resolv.conf:
# Generated by NetworkManager
domain home
search home
nameserver 10.123.123.1
Where's the issue?
(I have a response from Windows-user with openvpn client, that on his side DNS works fine, so it's an issue on my side.
Ok now I have another response (after I restarted openvpn service on server side) - it's not working.
I must say that it worked yesterday on my machine too.. so have I screwed up something on server? What could it be? )
Edit: Okay, I've got another Windows-user response (the same user as before) - it's working now. So.. I guess it was caused by openvpn restart and some delays with it. I haven't done anything since then. So we're back onto my machine.
I also traced that that wierd tun0 message appeared also yesterday, and yesterday it worked. Or maybe I added entry to resolv.conf by myself? I don't remember.. (damn it)
Solution 1:
This works for me: http://www.softwarepassion.com/solving-dns-problems-with-openvpn-on-ubuntu-box/
The important step is adding following two lines of configuration into your client openvpn config file:
up /etc/openvpn/update-resolv-conf
down /etc/openvpn/update-resolv-conf
Also ensure the resolvconf package is installed on the client, because that update-resolv-conf script depends on it.
It works with openvpn client service or command to start it manually.
However, the Ubuntu Network Manager doesn't this. It's an issue so far: https://bugs.launchpad.net/ubuntu/+source/openvpn/+bug/1211110
Solution 2:
Works for me after disabling NetworkManager's own dnsmasq.
Edit /etc/NetworkManager/NetworkManager.conf
#dns=dnsmasq
and restart NetworkManager
sudo restart network-manager
Solution 3:
Finally works (with standard NetworkManager and OVPN plugin)
nmcli -p connection modify MY_VPN_CONNECTION ipv4.never-default no
nmcli -p connection modify MY_VPN_CONNECTION ipv4.ignore-auto-dns no
nmcli -p connection modify MY_VPN_CONNECTION ipv4.dns-priority -42
In this case once VPN connection is established, all DNS requests are directed to VPN-supplied DNS servers without any manipulations with dnsmasq, up/down/dispatch helper scripts.