[CONFIGURATION] How do I get dhclient DHCPDISCOVER to stop attempting to connect unused devices?

[oshunluvr]

Doing some maintenance and saw this in syslog:

Apr 11 10:52:54 server dhclient[1284]: DHCPDISCOVER on wlp3s0 to 255.255.255.255 port 67 interval 3 (xid=0xeb150b26)
Apr 11 10:52:57 server dhclient[1284]: DHCPDISCOVER on wlp3s0 to 255.255.255.255 port 67 interval 8 (xid=0xeb150b26)
Apr 11 10:53:05 server dhclient[1284]: DHCPDISCOVER on wlp3s0 to 255.255.255.255 port 67 interval 8 (xid=0xeb150b26)
Apr 11 10:53:13 server dhclient[1284]: DHCPDISCOVER on wlp3s0 to 255.255.255.255 port 67 interval 19 (xid=0xeb150b26)
Apr 11 10:53:25 server dhclient[1284]: DHCPDISCOVER on enp2s0 to 255.255.255.255 port 67 interval 3 (xid=0x308f9905)
Apr 11 10:53:28 server dhclient[1284]: DHCPDISCOVER on enp2s0 to 255.255.255.255 port 67 interval 5 (xid=0x308f9905)
Apr 11 10:53:32 server dhclient[1284]: DHCPDISCOVER on wlp3s0 to 255.255.255.255 port 67 interval 10 (xid=0xeb150b26)
Apr 11 10:53:33 server dhclient[1284]: DHCPDISCOVER on enp2s0 to 255.255.255.255 port 67 interval 6 (xid=0x308f9905)
Apr 11 10:53:39 server dhclient[1284]: DHCPDISCOVER on enp2s0 to 255.255.255.255 port 67 interval 9 (xid=0x308f9905)
Apr 11 10:53:42 server dhclient[1284]: DHCPDISCOVER on wlp3s0 to 255.255.255.255 port 67 interval 11 (xid=0xeb150b26)
Apr 11 10:53:48 server dhclient[1284]: DHCPDISCOVER on enp2s0 to 255.255.255.255 port 67 interval 19 (xid=0x308f9905)
Apr 11 10:53:53 server dhclient[1284]: DHCPDISCOVER on wlp3s0 to 255.255.255.255 port 67 interval 10 (xid=0xeb150b26)
~~~

which repeats every three minutes forever. The two interfaces listed, wlp3s0 and enp2s0, are not connected or used. I'm using NetworkManager.

I tried just "ifdown"-ing both of them which just replaced the above messages with this:

Apr 11 10:17:14 server dhclient[1284]: DHCPDISCOVER on enp2s0 to 255.255.255.255 port 67 interval 8 (xid=0xe8cb2c39)
Apr 11 10:17:14 server dhclient[1284]: send_packet: Network is down
Apr 11 10:17:14 server dhclient[1284]: dhclient.c:2569: Failed to send 300 byte long packet over enp2s0 interface.
Apr 11 10:17:21 server dhclient[1284]: receive_packet failed on wlp3s0: Network is down
Apr 11 10:17:22 server dhclient[1284]: DHCPDISCOVER on enp2s0 to 255.255.255.255 port 67 interval 20 (xid=0xe8cb2c39)
Apr 11 10:17:22 server dhclient[1284]: send_packet: Network is down
~~~

but about twice as many lines as before.

I've down quite a bit of web searching, but no solutions yet. It doesn't seem to be causing any real problems, but I hate so much log spam.

[oshunluvr]

Contents of /etc/netplan/01-netcfg.yaml:

smith@server:~$ cat /etc/netplan/01-netcfg.yaml  
# This file describes the network interfaces available on your system
# For more information, see netplan(5).
network:
 version: 2
 renderer: NetworkManager
 ethernets:
   eno1:
     dhcp4: no
     dhcp6: no
#      addresses: [192.168.1.250/23]
#      gateway4: 192.168.1.1
#      nameservers:
#        addresses: [8.8.8.8,8.8.4.4]
   enp2s0:
     dhcp4: no
     dhcp4-overrides:  
       use-dns: false
     dhcp6: no
     dhcp6-overrides:
       use-dns: false
 wifis:
   wlp3s0:
     optional: true
     access-points:  
       "":
          password: ""
     dhcp4: no
     dhcp4-overrides:
       use-dns: false
     dhcp6: no
     dhcp6-overrides:
       use-dns: false

dev output from nmcli:

smith@server:~$ nmcli dev status
DEVICE  TYPE      STATE        CONNECTION  
eno1    ethernet  connected    eno1        
wlp3s0  wifi      unavailable  --          
enp2s0  ethernet  unmanaged    --          
lo      loopback  unmanaged    --

[Snowhog]

From Red Hat, but maybe useful: https://access.redhat.com/documentat...ing-networking

[oshunluvr]

Note that enp2s0 is already unmanaged and still shows in the logs. I went ahead and set wlp3s0 to unmanaged also for consistency.

[Snowhog]

Maybe https://raspberrypi.stackexchange.co...r-requests-why

[oshunluvr]

I purged isc-dhpc-client and -common and it STILL does this...

[oshunluvr]

Well, I finally added the two interfaces to NetworkManager.conf on the "unmanaged" line and REBOOTED and this seemed to stop the log spamming.

IDK if the nmcli has a bug that doesn't actually make the devices unmanaged or if I need to reboot after purging isc-dhcp-client, but one of them seems to have worked.



Now to figure out if I really need all 8 version of PHP i have installed...