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Alex
Asked: 2024-01-02 17:53:02 +0800 CST

How to fix problem with netplan configuration (ip address show) for Ubuntu 22.04?

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Using ubuntu 22.04 I tried to assign the two IP addresses 192.168.200.100 and 169.254.1.0 to the ethernet device enx00e04c680202. Following this tutorial and this answer I created a file /etc/netplan/01-network-config_home.yaml with the following content:

network:
  version: 2
  renderer: NetworkManager
  ethernets:
    enx00e04c680202:
      addresses:
        - 192.168.200.100/24
        - 169.254.1.100/24
      routes:
       - to: default
         via: 192.168.200.220
      nameservers:
        addresses:
          - 8.8.8.8   # Add your DNS server IP address
          - 8.8.4.4   # Add another DNS server IP address

and applied the changes using the command

sudo netplan apply

I checked the configuration with the command ip address show dev enx00e04c680202, but it seems only one address has been applied:

3: enx00e04c680202: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 00:e0:4c:68:02:02 brd ff:ff:ff:ff:ff:ff
    inet 192.168.200.100/24 brd 192.168.200.255 scope global noprefixroute enx00e04c680202
       valid_lft forever preferred_lft forever

But the other configured address seems to be working! Even it does not show up with the command

ip address show dev enx00e04c680202

I am able to connect to a device with IP address 169.254.1.0 that is connected only to that ethernet adapter.

When I add an IP address to that adapter enx00e04c680202 using the following command

sudo ip addr add 169.254.1.100/24 dev enx00e04c680202

then I see the following output of the command ip address show dev enx00e04c680202:

3: enx00e04c680202: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 00:e0:4c:68:02:02 brd ff:ff:ff:ff:ff:ff
    inet 192.168.200.100/24 brd 192.168.200.255 scope global noprefixroute enx00e04c680202
       valid_lft forever preferred_lft forever
    inet 169.254.1.100/24 scope global enx00e04c680202
       valid_lft forever preferred_lft forever

It shows the two IP addresses not only one. Maybe that is a bug with ip address show?

networking

1 Answers

  1. Best Answer

    You are trying to statically assign the address 169.254.1.100/24. The 169.254.0.0/16 address space is reserved for IPv4 autoconfiguration. It appears NetworkManager is refusing to allow you to statically assign an IP address in this range. You can enable use of an address in this range with the link-local directive, e.g.:

    enx00e04c680202:
  addresses:
    - 192.168.200.100/24
  routes:
   - to: default
     via: 192.168.200.220
     metric: 200
  link-local: [ ipv4, ipv6 ]

    See https://netplan.readthedocs.io/en/stable/netplan-yaml/#properties-for-all-device-types for an explanation of link-local.

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