[Bug 1759014] Re: Netplan has no way to control DHCP client

sismo 1759014 at bugs.launchpad.net
Sun Jun 21 04:00:26 UTC 2020


Hi all, I'm using ubuntu 20.04 on a raspberry pi (64bit version).  And
the problem is still present.  My netplan:

root at rbpi3-002:/etc/netplan# cat /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 to the
# internal DNS stub resolver of systemd-resolved. This file lists all
# configured search domains.
#
# Run "resolvectl status" to see details about the uplink DNS servers
# currently in use.
#
# 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.

nameserver 127.0.0.53
options edns0
search sismonda.local cpe.telecentro.net.ar
root at rbpi3-002:/etc/netplan# cat 50-cloud-init.yaml
# This file is generated from information provided by the datasource.  Changes
# to it will not persist across an instance reboot.  To disable cloud-init's
# network configuration capabilities, write a file
# /etc/cloud/cloud.cfg.d/99-disable-network-config.cfg with the following:
# network: {config: disabled}
network:
    version: 2
    ethernets:
        eth0:
            dhcp4: true
            dhcp6: false
            dhcp4-overrides:
                use-dns: false
            nameservers:
                search: [sismonda.local]
                addresses: [10.0.0.31,10.0.0.10,10.0.0.62]

The output of "systemd-resolve --status"

root at rbpi3-002:/etc/netplan# systemd-resolve --status
Global
       LLMNR setting: no
MulticastDNS setting: no
  DNSOverTLS setting: no
      DNSSEC setting: no
    DNSSEC supported: no
          DNSSEC NTA: 10.in-addr.arpa
                      16.172.in-addr.arpa
                      168.192.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
                      corp
                      d.f.ip6.arpa
                      home
                      internal
                      intranet
                      lan
                      local
                      private
                      test

Link 3 (wlan0)
      Current Scopes: none
DefaultRoute setting: no
       LLMNR setting: yes
MulticastDNS setting: no
  DNSOverTLS setting: no
      DNSSEC setting: no
    DNSSEC supported: no

Link 2 (eth0)
      Current Scopes: DNS
DefaultRoute setting: yes
       LLMNR setting: yes
MulticastDNS setting: no
  DNSOverTLS setting: no
      DNSSEC setting: no
    DNSSEC supported: no
         DNS Servers: 10.0.0.31
                      10.0.0.10
                      10.0.0.62
                      10.0.0.3
          DNS Domain: sismonda.local
                      cpe.telecentro.net.ar
root at rbpi3-002:/etc/netplan#


I found an extra dns and the domain search of my ISP!

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to systemd in Ubuntu.
https://bugs.launchpad.net/bugs/1759014

Title:
  Netplan has no way to control DHCP client

Status in netplan:
  Fix Released
Status in netplan.io package in Ubuntu:
  Fix Released
Status in systemd package in Ubuntu:
  Fix Released
Status in netplan.io source package in Bionic:
  Fix Released
Status in systemd source package in Bionic:
  Fix Released
Status in netplan.io source package in Cosmic:
  Fix Released
Status in systemd source package in Cosmic:
  Fix Released
Status in netplan.io source package in Disco:
  Fix Released
Status in systemd source package in Disco:
  Fix Released

Bug description:
  [Impact]
  DHCP configurations where custom settings (routes, nameservers, etc.) need to be applied.

  [Test case]
  1) Configure netplan for the particulars of the network by configuring an appropriate dhcp{4,6}-override stanza:

  network:
    version: 2
    ethernets:
      engreen:
        dhcp4: true
        dhcp4-overrides:
          use-dns: false
          use-routes: false
          route-metric: 3333

  Additionally, if so required, add a custom DNS / routes to the
  configuration. e.g.

        nameservers:
          search: [lab, kitchen]
          addresses: [8.8.8.8]

  (See https://netplan.io/reference#dhcp-overrides for the available
  options)

  2) Run 'netplan apply' or reboot to have the configuration applied.
  3) Validate that the routes / DNS are properly ignored and/or replaced by the defined values.

  [Regression potential]
  Minimal; this adds new values to the configuration generated for networkd or NetworkManager. Existing configurations will remain unchanged, but new configurations using the dhcp{4,6}-overrides fields will benefit from additional flexibility.

  
  ---

  
  Currently DHCP appears to be an all or nothing boolean, which is insufficient for many network configurations.

  Ideally all of the DHCP configuration options supported by systemd would also be supported in netplan:
  https://www.freedesktop.org/software/systemd/man/systemd.network.html#%5BDHCP%5D%20Section%20Options

  As an example, consider the following netplan configuration:

  network:
    version: 2
    renderer: networkd
    ethernets:
      enp0s3:
        dhcp4: yes
        nameservers: [8.8.8.8,8.8.4.4]

  After running netplan apply I check the nameservers with systemd-
  resolve --status and it shows:

  DNS Servers: 8.8.8.8
               8.8.4.4
               192.168.1.1

  Here, "192.168.1.1" was provided by my DHCP server.  On this
  particular node, I only want the manually configured DNS servers, but
  netplan has no way to indicate this.

To manage notifications about this bug go to:
https://bugs.launchpad.net/netplan/+bug/1759014/+subscriptions



More information about the foundations-bugs mailing list