[SOLVED] Unknown IP on Network-Interface

schmodd · 2023-02-24 11:22:15

Hi,

I just spotted an unknown ip-address (169.254.251.5/16) on my network-interface (enp3s0) that I never set up.
Output of "ip a":

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: enp3s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether d0:50:99:36:9a:4a brd ff:ff:ff:ff:ff:ff
    inet 169.254.251.5/16 metric 2048 brd 169.254.255.255 scope link enp3s0
       valid_lft forever preferred_lft forever
    inet 192.168.11.5/24 brd 192.168.11.255 scope global enp3s0
       valid_lft forever preferred_lft forever
3: wg0: <POINTOPOINT,NOARP,UP,LOWER_UP> mtu 1420 qdisc noqueue state UNKNOWN group default qlen 1000
    link/none
    inet 10.200.200.1/24 scope global wg0
       valid_lft forever preferred_lft forever

I am using systemd-networkd and here is my config:

[Match]
Name=enp3s0

[Network]
Address=192.168.11.5/24
Gateway=192.168.11.1
DNS=192.168.11.5
LinkLocalAddressing=ipv4

I couldn't spot any other network service - output of "systemd -t service":

 UNIT                                 LOAD   ACTIVE SUB     DESCRIPTION
  dbus.service                         loaded active running D-Bus System Message Bus
  getty@tty1.service                   loaded active running Getty on tty1
  kmod-static-nodes.service            loaded active exited  Create List of Static Device Nodes
  lighttpd.service                     loaded active running Lighttpd Web Server
  minidlna.service                     loaded active running minidlna server
  pihole-FTL.service                   loaded active running Pi-hole FTLDNS engine
  powertop.service                     loaded active exited  Powertop tunings
  smb.service                          loaded active running Samba SMB Daemon
  sshd.service                         loaded active running OpenSSH Daemon
  systemd-journal-flush.service        loaded active exited  Flush Journal to Persistent Storage
  systemd-journald.service             loaded active running Journal Service
  systemd-logind.service               loaded active running User Login Management
  systemd-network-generator.service    loaded active exited  Generate network units from Kernel command line
  systemd-networkd-wait-online.service loaded active exited  Wait for Network to be Configured
  systemd-networkd.service             loaded active running Network Configuration
  systemd-random-seed.service          loaded active exited  Load/Save OS Random Seed
  systemd-remount-fs.service           loaded active exited  Remount Root and Kernel File Systems
  systemd-sysctl.service               loaded active exited  Apply Kernel Variables
  systemd-timesyncd.service            loaded active running Network Time Synchronization
  systemd-tmpfiles-setup-dev.service   loaded active exited  Create Static Device Nodes in /dev
  systemd-tmpfiles-setup.service       loaded active exited  Create Volatile Files and Directories
  systemd-udev-trigger.service         loaded active exited  Coldplug All udev Devices
  systemd-udevd.service                loaded active running Rule-based Manager for Device Events and Files
  systemd-update-utmp.service          loaded active exited  Record System Boot/Shutdown in UTMP
  systemd-user-sessions.service        loaded active exited  Permit User Sessions
  unbound.service                      loaded active running Validating, recursive, and caching DNS resolver
  user-runtime-dir@1000.service        loaded active exited  User Runtime Directory /run/user/1000
  user@1000.service                    loaded active running User Manager for UID 1000
  wg-quick@wg0.service                 loaded active exited  WireGuard via wg-quick(8) for wg0

I am currently searching the whole filesystem for the ip - so far i haven't found any file that contains it.
Any idea where this ip comes from or which service is responsible for it?

Last edited by schmodd (2023-02-24 14:06:40)

seth · 2023-02-24 13:15:34

whois 169.254.251.5

See the comments there.

schmodd · 2023-02-24 13:22:54

Thanks for your answer.
I know that is a link local address, but why is it active?
As mentioned above I set up a manual address.

seth · 2023-02-24 13:33:28

LinkLocalAddressing=ipv4

?

schmodd · 2023-02-24 13:41:57

Thanks, that option disabled it (when commented).
I still dont understand why "LinkLocalAddressing=ipv4" enables link local address even though a manual address is active.
I had this option active for some time and it never created a link local address.

seth · 2023-02-24 13:48:14

https://man.archlinux.org/man/systemd.network.5 wrote:

LinkLocalAddressing=
Enables link-local address autoconfiguration. Accepts yes, no, ipv4, and ipv6. An IPv6 link-local address is configured when yes or ipv6. An IPv4 link-local address is configured when yes or ipv4 and when DHCPv4 autoconfiguration has been unsuccessful for some time. (IPv4 link-local address autoconfiguration will usually happen in parallel with repeated attempts to acquire a DHCPv4 lease).
Defaults to no when KeepMaster= or Bridge= is set or when the specified MACVLAN=/MACVTAP= has Mode=passthru, or ipv6 otherwise.

I guess you were looking for "none" because of https://wiki.archlinux.org/title/IPv6#s … networkd_3 ?

schmodd · 2023-02-24 13:57:57

Is that a typo on your side? none -> no?
Anyway "LinkLocalAddressing=no" fixed it.
Thank you.

seth · 2023-02-24 14:05:16

Let's call it a typo… (EBBAF)

Please always remember to mark resolved threads by editing your initial posts subject - so others will know that there's no task left, but maybe a solution to find.
Thanks.

Arch Linux

#1 2023-02-24 11:22:15

[SOLVED] Unknown IP on Network-Interface

#2 2023-02-24 13:15:34

Re: [SOLVED] Unknown IP on Network-Interface

#3 2023-02-24 13:22:54

Re: [SOLVED] Unknown IP on Network-Interface

#4 2023-02-24 13:33:28

Re: [SOLVED] Unknown IP on Network-Interface

#5 2023-02-24 13:41:57

Re: [SOLVED] Unknown IP on Network-Interface

#6 2023-02-24 13:48:14

Re: [SOLVED] Unknown IP on Network-Interface

#7 2023-02-24 13:57:57

Re: [SOLVED] Unknown IP on Network-Interface

#8 2023-02-24 14:05:16

Re: [SOLVED] Unknown IP on Network-Interface

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