[systemd-devel] How to autoconfigure IPv4 LinkLocalAddressing

[Muggeridge, Matt]

Hi,

I’m using systemd_254.

I my ".network" configuration file (see below), I'm expecting that the “mul0” interface will always be assigned an IPv4 link local address. The documentation for LinkLocalAddressing describes:

    > An IPv4 link-local address is configured when yes or ipv4 and when DHCPv4
    > autoconfiguration has been unsuccessful for some time.

I don't run a DHCP Client on this interface and RFC3927 (last paragraph p.8) states it should be independent of DHCP:

    > The assignment of an IPv4 Link-Local address on an interface is
    > based solely on the state of the interface, and is independent
    > of any other protocols such as DHCP.

How do I autoconfigure an IPv4 link local address on this interface?

FWIW: In case my procedure for reconfiguring is wrong, after changing the ".network" file, I run:

      $ networkctl reload; entworkctl reconfigure mul0; ip a show dev mul0

Here's my config file:

------------------------------------------------------------
$ networkctl cat 50-mul0.network
# /lib/systemd/network/50-mul0.network
[Match]
Name=mul0

[Network]
# DHCP=ipv4
LinkLocalAddressing=ipv4
ConfigureWithoutCarrier=true

#[DHCPv4]
#MaxAttempts=1

$ ip a show dev mul0
7: mul0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOWN group default qlen 1000
    link/ether 00:50:b6:15:53:4d brd ff:ff:ff:ff:ff:ff
    altname enu1

$ networkctl status mul0
● 7: mul0                                                                  
                     Link File: /lib/systemd/network/99-default.link
                  Network File: /lib/systemd/network/50-mul0.network
                         State: no-carrier (configuring)
                  Online state: offline
                          Type: ether
                          Path: platform-xhci-hcd.0.auto-usb-0:1:1.0
                        Driver: asix
                        Vendor: ASIX_Elec._Corp.
                         Model: AX88772B
             Alternative Names: enu1
              Hardware Address: 00:50:b6:15:53:4d
                           MTU: 1500 (max: 65535)
                         QDisc: pfifo_fast
  IPv6 Address Generation Mode: none
      Number of Queues (Tx/Rx): 1/1
              Auto negotiation: yes
                         Speed: 100Mbps
                        Duplex: full
                          Port: tp
             Activation Policy: up
           Required For Online: yes

Aug 31 23:28:14 sph-018-rmc systemd-networkd[3942]: mul0: DHCPv6 lease lost
Aug 31 23:28:58 sph-018-rmc systemd-networkd[3942]: mul0: Reconfiguring with /lib/systemd/…ork.
Aug 31 23:28:58 sph-018-rmc systemd-networkd[3942]: mul0: DHCPv6 lease lost
Aug 31 23:28:58 sph-018-rmc systemd-networkd[3942]: mul0: Configuring with /lib/systemd/ne…ork.
Aug 31 23:32:01 sph-018-rmc systemd-networkd[3942]: mul0: Reconfiguring with /lib/systemd/…ork.
Aug 31 23:32:01 sph-018-rmc systemd-networkd[3942]: mul0: Configuring with /lib/systemd/ne…ork.
Aug 31 23:50:09 sph-018-rmc systemd-networkd[3942]: mul0: Reconfiguring with /lib/systemd/…ork.
Aug 31 23:50:09 sph-018-rmc systemd-networkd[3942]: mul0: Configuring with /lib/systemd/ne…ork.
Aug 31 23:55:45 sph-018-rmc systemd-networkd[3942]: mul0: Reconfiguring with /lib/systemd/…ork.
Aug 31 23:55:45 sph-018-rmc systemd-networkd[3942]: mul0: Configuring with /lib/systemd/ne…ork
--------------------------

Thanks,
Matt.