excessive ipv6 adding/deleting default route in artful

[Tiago Stürmer Daitx]

Package: dhcpcd5
Version: 6.11.5-0ubuntu1
Release: artful

dhcpcd5 in artful is outputting repeated messages about adding/deleting ipv6 default routes. I didn't check other releases.

The actual log is not the problem, but the actual behavior seems to be: I don't expect dhcpcd to be adding a default route only to then instantly remove it.

The only similar issue I could find was this one:
https://serverfault.com/questions/846019/dhcpcd-ipv6-excessive-adding-removing-route-in-log
but the solution presented there (removing the route manually) does not work on this case.
I found nothing in dhcpcd bug tracking tool at https://dev.marples.name/maniphest/query/all/

Copy & paste from syslog:
Jun 7 17:10:18 localhost dhcpcd[1585]: wlan0: adding default route via fe80::1:1
Jun 7 17:10:18 localhost dhcpcd[1585]: wlan0: deleted default route via fe80::1:1
Jun 7 17:10:23 localhost dhcpcd[1585]: wlan0: adding default route via fe80::1:1
Jun 7 17:10:23 localhost dhcpcd[1585]: wlan0: deleted default route via fe80::1:1
Jun 7 17:10:29 localhost dhcpcd[1585]: wlan0: adding default route via fe80::1:1
Jun 7 17:10:29 localhost dhcpcd[1585]: wlan0: deleted default route via fe80::1:1
Jun 7 17:10:36 localhost dhcpcd[1585]: wlan0: adding default route via fe80::1:1
Jun 7 17:10:36 localhost dhcpcd[1585]: wlan0: deleted default route via fe80::1:1
Jun 7 17:10:43 localhost dhcpcd[1585]: wlan0: adding default route via fe80::1:1
Jun 7 17:10:43 localhost dhcpcd[1585]: wlan0: deleted default route via fe80::1:1
Jun 7 17:10:49 localhost dhcpcd[1585]: wlan0: adding default route via fe80::1:1
Jun 7 17:10:49 localhost dhcpcd[1585]: wlan0: deleted default route via fe80::1:1
Jun 7 17:10:56 localhost dhcpcd[1585]: wlan0: adding default route via fe80::1:1
Jun 7 17:10:56 localhost dhcpcd[1585]: wlan0: deleted default route via fe80::1:1
Jun 7 17:11:02 localhost dhcpcd[1585]: wlan0: adding default route via fe80::1:1
Jun 7 17:11:02 localhost dhcpcd[1585]: wlan0: deleted default route via fe80::1:1
Jun 7 17:11:08 localhost dhcpcd[1585]: wlan0: adding default route via fe80::1:1
Jun 7 17:11:08 localhost dhcpcd[1585]: wlan0: deleted default route via fe80::1:1
Jun 7 17:11:15 localhost dhcpcd[1585]: wlan0: adding default route via fe80::1:1
Jun 7 17:11:15 localhost dhcpcd[1585]: wlan0: deleted default route via fe80::1:1
Jun 7 17:11:19 localhost dhcpcd[1585]: wlan0: adding default route via fe80::1:1
Jun 7 17:11:19 localhost dhcpcd[1585]: wlan0: deleted default route via fe80::1:1
Jun 7 17:11:22 localhost dhcpcd[1585]: wlan0: adding default route via fe80::1:1
Jun 7 17:11:22 localhost dhcpcd[1585]: wlan0: deleted default route via fe80::1:1
Jun 7 17:11:26 localhost dhcpcd[1585]: wlan0: adding default route via fe80::1:1
Jun 7 17:11:26 localhost dhcpcd[1585]: wlan0: deleted default route via fe80::1:1
Jun 7 17:11:33 localhost dhcpcd[1585]: wlan0: adding default route via fe80::1:1
Jun 7 17:11:33 localhost dhcpcd[1585]: wlan0: deleted default route via fe80::1:1
Jun 7 17:11:38 localhost dhcpcd[1585]: wlan0: adding default route via fe80::1:1
Jun 7 17:11:38 localhost dhcpcd[1585]: wlan0: deleted default route via fe80::1:1
Jun 7 17:11:48 localhost dhcpcd[1585]: wlan0: adding default route via fe80::1:1
Jun 7 17:11:48 localhost dhcpcd[1585]: wlan0: deleted default route via fe80::1:1
Jun 7 17:11:56 localhost dhcpcd[1585]: wlan0: adding default route via fe80::1:1
Jun 7 17:11:56 localhost dhcpcd[1585]: wlan0: deleted default route via fe80::1:1
Jun 7 17:12:05 localhost dhcpcd[1585]: wlan0: adding default route via fe80::1:1
Jun 7 17:12:05 localhost dhcpcd[1585]: wlan0: deleted default route via fe80::1:1
Jun 7 17:12:14 localhost dhcpcd[1585]: wlan0: adding default route via fe80::1:1
Jun 7 17:12:14 localhost dhcpcd[1585]: wlan0: deleted default route via fe80::1:1
Jun 7 17:12:17 localhost dhcpcd[1585]: wlan0: adding default route via fe80::1:1
Jun 7 17:12:17 localhost dhcpcd[1585]: wlan0: deleted default route via fe80::1:1
Jun 7 17:12:27 localhost dhcpcd[1585]: wlan0: adding default route via fe80::1:1
Jun 7 17:12:27 localhost dhcpcd[1585]: wlan0: deleted default route via fe80::1:1
Jun 7 17:12:34 localhost dhcpcd[1585]: wlan0: adding default route via fe80::1:1
Jun 7 17:12:34 localhost dhcpcd[1585]: wlan0: deleted default route via fe80::1:1
Jun 7 17:12:37 localhost dhcpcd[1585]: wlan0: adding default route via fe80::1:1
Jun 7 17:12:37 localhost dhcpcd[1585]: wlan0: deleted default route via fe80::1:1

======================
$ cat /etc/dhcpcd.conf
# A sample configuration for dhcpcd.
# See dhcpcd.conf(5) for details.

# Allow users of this group to interact with dhcpcd via the control socket.
#controlgroup wheel

# Inform the DHCP server of our hostname for DDNS.
hostname

# Use the hardware address of the interface for the Client ID.
#clientid
# or
# Use the same DUID + IAID as set in DHCPv6 for DHCPv4 ClientID as per RFC4361.
# Some non-RFC compliant DHCP servers do not reply with this set.
# In this case, comment out duid and enable clientid above.
duid

# Persist interface configuration when dhcpcd exits.
persistent

# Rapid commit support.
# Safe to enable by default because it requires the equivalent option set
# on the server to actually work.
option rapid_commit

# A list of options to request from the DHCP server.
option domain_name_servers, domain_name, domain_search, host_name
option classless_static_routes
# Most distributions have NTP support.
option ntp_servers
# Respect the network MTU. This is applied to DHCP routes.
option interface_mtu

# A ServerID is required by RFC2131.
require dhcp_server_identifier

# Generate Stable Private IPv6 Addresses instead of hardware based ones
slaac private

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Martin-Éric Racine (q-funk)]

You probably have the same interface defined in /etc/network/interfaces and configure to use auto. If that's the case, commenting it out should solve the issue.

[Martin-Éric Racine (q-funk)]

Has the fix I suggested above solved the issue or not?

[Martin-Éric Racine (q-funk)]

This was reported against a really old version. Closing. Feel free to re-open if the bug still exists with current versions.