Hello!
I installed docker by following the instructions here:
I am on armbian buster (10). The problem is that docker0 breaks dns of the host and I can not figure out why. Dns does not work for containers either.
nmcli dev show | grep 'IP4.DNS'
IP4.DNS[1]: 192.168.1.1
sudo route
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
default _gateway 0.0.0.0 UG 100 0 0 eth0
link-local 0.0.0.0 255.255.0.0 U 1000 0 0 eth0
172.17.0.0 0.0.0.0 255.255.0.0 U 0 0 0 docker0
192.168.1.0 0.0.0.0 255.255.255.0 U 100 0 0 eth0
sudo ifconfig
docker0: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500
inet 172.17.0.1 netmask 255.255.0.0 broadcast 172.17.255.255
ether 02:42:7b:98:37:66 txqueuelen 0 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.1.160 netmask 255.255.255.0 broadcast 192.168.1.255
inet6 fe80::2974:98e8:289b:f3fb prefixlen 64 scopeid 0x20<link>
ether 82:38:2f:c9:e0:80 txqueuelen 1000 (Ethernet)
RX packets 1599 bytes 254405 (248.4 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 1289 bytes 489915 (478.4 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
device interrupt 24
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 1 (Local Loopback)
RX packets 3150 bytes 1106993 (1.0 MiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 3150 bytes 1106993 (1.0 MiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
If I remove docker0 things work again.
sudo systemd-resolve status
status: resolve call failed: All attempts to contact name servers or networks failed
I dont understand what the problem is. I would really appreciate if someone could explain what is going wrong here.
By adding:
search lan
nameserver 192.168.1.1
to /etc/resolv.conf it works, but this does not survive a reboot.
Contents of /etc/resolv.conf:
# This file is managed by man:systemd-resolved(8). Do not edit.
#
# This is a dynamic resolv.conf file for connecting local clients directly to
# all known uplink DNS servers. This file lists all configured search domains.
#
# Third party programs must not access this file directly, but only through the
# symlink at /etc/resolv.conf. To manage man:resolv.conf(5) in a different way,
# replace this symlink by a static file or a different symlink.
#
# See man:systemd-resolved.service(8) for details about the supported modes of
# operation for /etc/resolv.conf.
# No DNS servers known.
sudo systemd-resolve status
status: resolve call failed: All attempts to contact name servers or networks failed
Contens of /etc/resolv.conf without docker:
# Generated by NetworkManager
search lan
nameserver 192.168.1.1
journalctl -u systemd-resolved -f
-- Logs begin at Thu 2019-07-11 15:18:34 CEST. --
Jul 11 15:18:36 rockpro64 systemd[1]: Starting Network Name Resolution...
Jul 11 15:18:36 rockpro64 systemd-resolved[537]: Positive Trust Anchors:
Jul 11 15:18:36 rockpro64 systemd-resolved[537]: . IN DS 19036 8 2 49aac11d7b6f6446702e54a1607371607a1a41855200fd2ce1cdde32f24e8fb5
Jul 11 15:18:36 rockpro64 systemd-resolved[537]: . IN DS 20326 8 2 e06d44b80b8f1d39a95c0b0d7c65d08458e880409bbc683457104237c7f8ec8d
Jul 11 15:18:36 rockpro64 systemd-resolved[537]: Negative trust anchors: 10.in-addr.arpa 16.172.in-addr.arpa 17.172.in-addr.arpa 18.172.in-addr.arpa 19.172.in-addr.arpa 20.172.in-addr.arpa 21.172.in-addr.arpa 22.172.in-addr.arpa 23.172.in-addr.arpa 24.172.in-addr.arpa 25.172.in-addr.arpa 26.172.in-addr.arpa 27.172.in-addr.arpa 28.172.in-addr.arpa 29.172.in-addr.arpa 30.172.in-addr.arpa 31.172.in-addr.arpa 168.192.in-addr.arpa d.f.ip6.arpa corp home internal intranet lan local private test
Jul 11 15:18:36 rockpro64 systemd-resolved[537]: Using system hostname 'rockpro64'.
Jul 11 15:18:36 rockpro64 sh[638]: /etc/resolvconf/update.d/libc: Warning: /etc/resolv.conf is not a symbolic link to /etc/resolvconf/run/resolv.conf
Jul 11 15:18:36 rockpro64 systemd[1]: Started Network Name Resolution.