Table of Contents
Ubuntu 18.04 Netplan
Intro
Ubuntu 18.04 used a YAML based file with Netplan to configure the networking. I need to set up a server for virtualisation hosting with bonded uplinks to the ethernet switch.
This page build on the basic config to have a bonded ethernet with a vlan driver next to pick off vlans from the bond0 interface, and then the bridging driver on the vlans to allow a guest to connect to any vlan presented.
Basic DHCP YAML config
network: version: 2 renderer: networkd ethernets: ens3: dhcp4: yes
Basic static address
network: version: 2 renderer: networkd ethernets: ens3: addresses: - 192.168.5.YYY/24 gateway4: 192.168.5.ZZZ nameservers: search: [rainsbrook.co.uk, sub.rainsbrook.co.uk] addresses: [192.168.5.XXX, 1.1.1.1]
Static with Bonding
And VLANs
And Bridging on VLANS on Bonding
This renames the “newer” style of naming ethernet to the more traditional eth0/1/2 etc based on the MAC address of the interface.
network: version: 2 renderer: networkd ethernets: eth0: match: macaddress: 00:30:48:c0:ff:ee dhcp4: no dhcp6: no optional: true set-name: eth0 eth1: match: macaddress: 00:fe:de:ad:be:ef dhcp4: no dhcp6: no optional: true set-name: eth1 bonds: bond0: interfaces: [ eth0, eth1 ] dhcp4: no dhcp6: no parameters: mode: active-backup primary: eth0 vlans: vlan5: accept-ra: no id: 5 link: bond0 dhcp4: no dhcp6: no vlans: vlan7: accept-ra: no id: 7 link: bond0 dhcp4: no dhcp6: no bridges: br1: addresses: [ 192.168.1.x/24 ] dhcp4: no dhcp6: no interfaces: [ bond0 ] gateway4: 192.168.1.1 nameservers: addresses: [ 192.168.1.x ] search: [ domain1.co.uk, domain1.int ] br5: dhcp4: no dhcp6: no interfaces: [ vlan5 ] br7: dhcp4: no dhcp6: no interfaces: [ vlan7 ]
Updating resolv.conf
/etc/resolv/conf
is now a symlink as below:-
root@argon:~# ls -l /etc/resolv.conf lrwxrwxrwx 1 root root 39 Apr 3 08:41 /etc/resolv.conf -> ../run/systemd/resolve/stub-resolv.conf root@argon:~# ls -l /run/systemd/resolve/* -rw-r--r-- 1 systemd-resolve systemd-resolve 633 Apr 3 12:04 /run/systemd/resolve/resolv.conf -rw-r--r-- 1 systemd-resolve systemd-resolve 760 Apr 3 12:04 /run/systemd/resolve/stub-resolv.conf
Two choices seem to exist, the resolv.conf file is the one updated by netplan, so let's use this:-
root@argon:~# ln -s /run/systemd/resolve/resolv.conf /etc/resolv.conf ln: failed to create symbolic link '/etc/resolv.conf': File exists root@argon:~# mv /etc/resolv.conf /etc/resolv.conf.orig root@argon:~# ln -s /run/systemd/resolve/resolv.conf /etc/resolv.conf root@argon:~# rm /etc/resolv.conf.orig
You could just use ln -sf
to force the link creation, but if something goes wrong, you loose the original file.
Test with dig
or nslookup
and resolution should work as expected.