networking – No DHCP Offer Through Switch

Issue

Ubuntu will not connect to my network when using a switch. It will connect if wired directly into the router.

My wife has ‘asked’ that I don’t have cables in the hallway anymore (especially with a baby that should be crawling soon) and the router needs to stay where it is, so connecting directly to the router is not an option.

Summary

I am new at Ubuntu/Linux, and I am now way over my head. Shocking, I know. I’ve been at this for a couple of weeks now, and have scoured the internet for an answer with no luck.
Hopefully I haven’t missed something and are wasting your time.

I have a Ubuntu computer that I am using for a home server.
It connects to the network without a hitch if I connect it straight into the router.
It is refusing to connect to the internet when I put a switch between it and the router.
The network client is stuck on “connecting” and gives ‘activation of network connection failed.’
As far as I can tell, the server seems to be having trouble getting a DHCP response.

I’m hoping someone who sees this can help point me in the correct direction. Okay, let’s not kid ourselves, I’m hoping someone knows the answer, but I’ll take what I can get. Happy to provide any more info.

Network Map

Network Map

In this image, all red lines are lines that don’t work and the green is the line that does work.

Specs

  • OS: Ubuntu 20.04.2 LTS (was on Ubuntu 16.something, same results)
  • Processor: Intel Xeon(R) CPU X3450 @ 2.67GHz x 8
  • NIC 1 (AKA enp4s0): Intel Corporation 82574L Gigabit Network Connection
  • NIC 2 (AKA enp5s0): Intel Corporation 82574L Gigabit Network Connection
  • Router: Arris NVG468MQ (Had a different router a couple weeks ago. Same results)
  • Switch: Netgear GS305 (Also tried a TP-Link TL-SGG105 and a TP-Link SF1008D)

Notes

  • Manually setting the IP address does not fix the issue.
  • Both of the NIC cards have the same issue.
  • All ethernet cables are cat 5e or cat 6 cables
  • Issue presents itself on installed OSs (20.04.2 and 16.something), a pupply linux live CD, and an ubuntu 20.04.2 live USB.
  • For the most part, the server does not show up in any of the router’s admin pages/device lists
  • After the following command, which someone says makes the network interface ‘promiscuous,’ the server showed up in the router’s devices list, but the network still didn’t work: “`$ sudo tcpdump -n udp port 68 -vv“`
  • Currently on a brand new, fully updated installation
  • Server has been rebooted multiple times
  • “dhclient -r” has no noticable affect
  • “dhclient enp4s0” has no noticable affect

Terminal Results

$ lspci | grep Ethernet

04:00.0 Ethernet controller: Intel Corporation 82574L Gigabit Network Connection
05:00.0 Ethernet controller: Intel Corporation 82574L Gigabit Network Connection

$ cat /etc/NetworkManager/NetworkManager.conf

(main)
plugins=ifupdown,keyfile
(ifupdown)
managed=false
(device)
wifi.scan-rand-mac-address=no

$ sudo dhclient -v enp4s0

Internet Systems Consortium DHCP Client 4.4.1
Copyright 2004-2018 Internet Systems Consortium.
All rights reserved.
For info, please visit https://www.isc.org/software/dhcp/
Listening on LPF/enp4s0/90:e6:ba:92:24:94
Sending on LPF/enp4s0/90:e6:ba:92:24:94
Sending on Socket/fallback
DHCPDISCOVER on enp4s0 to 255.255.255.255 port 67 interval 3 (xid=0xb03b7843)
DHCPDISCOVER on enp4s0 to 255.255.255.255 port 67 interval 3 (xid=0xb03b7843)
DHCPDISCOVER on enp4s0 to 255.255.255.255 port 67 interval 4 (xid=0xb03b7843)
DHCPDISCOVER on enp4s0 to 255.255.255.255 port 67 interval 7 (xid=0xb03b7843)
DHCPDISCOVER on enp4s0 to 255.255.255.255 port 67 interval 10 (xid=0xb03b7843)
DHCPDISCOVER on enp4s0 to 255.255.255.255 port 67 interval 16 (xid=0xb03b7843)
DHCPDISCOVER on enp4s0 to 255.255.255.255 port 67 interval 20 (xid=0xb03b7843)
DHCPDISCOVER on enp4s0 to 255.255.255.255 port 67 interval 18 (xid=0xb03b7843)
DHCPDISCOVER on enp4s0 to 255.255.255.255 port 67 interval 21 (xid=0xb03b7843)
DHCPDISCOVER on enp4s0 to 255.255.255.255 port 67 interval 12 (xid=0xb03b7843)
DHCPDISCOVER on enp4s0 to 255.255.255.255 port 67 interval 20 (xid=0xb03b7843)
DHCPDISCOVER on enp4s0 to 255.255.255.255 port 67 interval 14 (xid=0xb03b7843)
DHCPDISCOVER on enp4s0 to 255.255.255.255 port 67 interval 14 (xid=0xb03b7843)
DHCPDISCOVER on enp4s0 to 255.255.255.255 port 67 interval 13 (xid=0xb03b7843)
DHCPDISCOVER on enp4s0 to 255.255.255.255 port 67 interval 16 (xid=0xb03b7843)
DHCPDISCOVER on enp4s0 to 255.255.255.255 port 67 interval 16 (xid=0xb03b7843)
DHCPDISCOVER on enp4s0 to 255.255.255.255 port 67 interval 17 (xid=0xb03b7843)
DHCPDISCOVER on enp4s0 to 255.255.255.255 port 67 interval 12 (xid=0xb03b7843)
DHCPDISCOVER on enp4s0 to 255.255.255.255 port 67 interval 9 (xid=0xb03b7843)
DHCPDISCOVER on enp4s0 to 255.255.255.255 port 67 interval 13 (xid=0xb03b7843)
DHCPDISCOVER on enp4s0 to 255.255.255.255 port 67 interval 7 (xid=0xb03b7843)
DHCPDISCOVER on enp4s0 to 255.255.255.255 port 67 interval 11 (xid=0xb03b7843)
DHCPDISCOVER on enp4s0 to 255.255.255.255 port 67 interval 11 (xid=0xb03b7843)
DHCPDISCOVER on enp4s0 to 255.255.255.255 port 67 interval 8 (xid=0xb03b7843)
DHCPDISCOVER on enp4s0 to 255.255.255.255 port 67 interval 6 (xid=0xb03b7843)
No DHCPOFFERS received.
No working leases in persistent database – sleeping.

$ sudo tail -f /var/log/syslog

(sudo) password for andrew:
May 30 12:57:48 FemmiServ avahi-daemon(644): Withdrawing address record for
fe80::6e01:80b5:40b3:8ccd on enp4s0.
    
    May 30 12:57:48 FemmiServ avahi-daemon(644): Leaving mDNS multicast group on interface
    enp4s0.IPv6 with address fe80::6e01:80b5:40b3:8ccd.
    May 30 12:57:48 FemmiServ avahi-daemon(644): Interface enp4s0.IPv6 no longer relevant for mDNS.
    May 30 12:57:49 FemmiServ NetworkManager(648): <info> (1622404669.0053) dhcp4 (enp4s0):
    canceled DHCP transaction
    May 30 12:57:49 FemmiServ NetworkManager(648): <info> (1622404669.0054) dhcp4 (enp4s0): state
    changed timeout -> done
    May 30 12:57:49 FemmiServ dbus-daemon(647): (system) Activating via systemd: service
    name='org.freedesktop.nm_dispatcher' unit='dbus-org.freedesktop.nm-dispatcher.service' requested by
    ':1.12' (uid=0 pid=648 comm="/usr/sbin/NetworkManager --no-daemon " label="unconfined")
    May 30 12:57:49 FemmiServ systemd(1): Starting Network Manager Script Dispatcher Service...
    May 30 12:57:49 FemmiServ dbus-daemon(647): (system) Successfully activated service
    'org.freedesktop.nm_dispatcher'
    May 30 12:57:49 FemmiServ systemd(1): Started Network Manager Script Dispatcher Service.
    May 30 12:57:58 FemmiServ systemd(1): NetworkManager-dispatcher.service: Succeeded.
    May 30 13:01:13 FemmiServ dbus-daemon(647): (system) Activating via systemd: service
    name='org.freedesktop.hostname1' unit='dbus-org.freedesktop.hostname1.service' requested by ':1.76'
    (uid=1000 pid=1909 comm="gnome-control-center network " label="unconfined")
    May 30 13:01:13 FemmiServ systemd(1): Starting Hostname Service...
    May 30 13:01:13 FemmiServ dbus-daemon(647): (system) Successfully activated service
    'org.freedesktop.hostname1'
    May 30 13:01:13 FemmiServ systemd(1): Started Hostname Service.
    
    May 30 13:01:21 FemmiServ NetworkManager(648): <info> (1622404881.6479) audit: op="connection-
    update" uuid="3f27339b-ac78-3932-a93a-0348c70a25af" name="Wired connection 1"
    
    args="connection.timestamp,ipv6.method" pid=1909 uid=1000 result="success"
    May 30 13:01:21 FemmiServ NetworkManager(648): <info> (1622404881.6486) policy: auto-activating
    connection 'Wired connection 1' (3f27339b-ac78-3932-a93a-0348c70a25af)
    May 30 13:01:21 FemmiServ NetworkManager(648): <info> (1622404881.6529) device (enp4s0):
    Activation: starting connection 'Wired connection 1' (3f27339b-ac78-3932-a93a-0348c70a25af)
    May 30 13:01:21 FemmiServ NetworkManager(648): <info> (1622404881.6531) device (enp4s0): state
    change: disconnected -> prepare (reason 'none', sys-iface-state: 'managed')
    May 30 13:01:21 FemmiServ NetworkManager(648): <info> (1622404881.6539) manager:
    NetworkManager state is now CONNECTING
    May 30 13:01:21 FemmiServ NetworkManager(648): <info> (1622404881.6543) device (enp4s0): state
    change: prepare -> config (reason 'none', sys-iface-state: 'managed')
    May 30 13:01:21 FemmiServ NetworkManager(648): <info> (1622404881.6558) device (enp4s0): state
    change: config -> ip-config (reason 'none', sys-iface-state: 'managed')
    May 30 13:01:21 FemmiServ NetworkManager(648): <info> (1622404881.6562) dhcp4 (enp4s0):
    activation: beginning transaction (timeout in 45 seconds)
    May 30 13:01:23 FemmiServ avahi-daemon(644): Joining mDNS multicast group on interface
    enp4s0.IPv6 with address fe80::92e6:baff:fe92:2494.
    May 30 13:01:23 FemmiServ avahi-daemon(644): New relevant interface enp4s0.IPv6 for mDNS.
    May 30 13:01:23 FemmiServ avahi-daemon(644): Registering new address record for
    fe80::92e6:baff:fe92:2494 on enp4s0.*.
    May 30 13:01:43 FemmiServ dbus-daemon(867): (session uid=1000 pid=867) Activating via systemd:
    service name='org.bluez.obex' unit='dbus-org.bluez.obex.service' requested by ':1.136' (uid=1000
    pid=1909 comm="gnome-control-center network " label="unconfined")
    May 30 13:01:43 FemmiServ systemd(1): systemd-hostnamed.service: Succeeded.
    May 30 13:01:43 FemmiServ systemd(801): Starting Bluetooth OBEX service...
    May 30 13:01:43 FemmiServ obexd(2604): OBEX daemon 5.53
    May 30 13:01:43 FemmiServ dbus-daemon(867): (session uid=1000 pid=867) Successfully activated
    service 'org.bluez.obex'
    May 30 13:01:43 FemmiServ systemd(801): Started Bluetooth OBEX service.
    May 30 13:02:03 FemmiServ dbus-daemon(647): (system) Activating via systemd: service
    name='org.freedesktop.nm_dispatcher' unit='dbus-org.freedesktop.nm-dispatcher.service' requested by
    ':1.12' (uid=0 pid=648 comm="/usr/sbin/NetworkManager --no-daemon " label="unconfined")
    May 30 13:02:03 FemmiServ systemd(1): Starting Network Manager Script Dispatcher Service...
    
    May 30 13:02:03 FemmiServ dbus-daemon(647): (system) Successfully activated service
    'org.freedesktop.nm_dispatcher'
    May 30 13:02:03 FemmiServ systemd(1): Started Network Manager Script Dispatcher Service.
    May 30 13:02:06 FemmiServ NetworkManager(648): <warn> (1622404926.9662) dhcp4 (enp4s0):
    request timed out
    May 30 13:02:06 FemmiServ NetworkManager(648): <info> (1622404926.9662) dhcp4 (enp4s0): state
    changed unknown -> timeout
    May 30 13:02:06 FemmiServ NetworkManager(648): <info> (1622404926.9663) device (enp4s0): state
    change: ip-config -> failed (reason 'ip-config-unavailable', sys-iface-state: 'managed')
    May 30 13:02:06 FemmiServ NetworkManager(648): <info> (1622404926.9673) manager:
    NetworkManager state is now DISCONNECTED
    May 30 13:02:06 FemmiServ NetworkManager(648): <warn> (1622404926.9696) device (enp4s0):
    Activation: failed for connection 'Wired connection 1'
    May 30 13:02:06 FemmiServ NetworkManager(648): <info> (1622404926.9704) device (enp4s0): state
    change: failed -> disconnected (reason 'none', sys-iface-state: 'managed')
    May 30 13:02:06 FemmiServ avahi-daemon(644): Withdrawing address record for
    fe80::92e6:baff:fe92:2494 on enp4s0.

$ journalctl

-- Logs begin at Sun 2021-05-30 12:30:22 PDT, end at Sun 2021-05-30 12:57:49 PD>
    May 30 12:30:22 FemmiServ kernel: microcode: microcode updated early to revisio>
    May 30 12:30:22 FemmiServ kernel: Linux version 5.8.0-43-generic (buildd@lcy01->
    May 30 12:30:22 FemmiServ kernel: Command line: BOOT_IMAGE=/boot/vmlinuz-5.8.0->
    May 30 12:30:22 FemmiServ kernel: KERNEL supported cpus:
    May 30 12:30:22 FemmiServ kernel: Intel GenuineIntel
    May 30 12:30:22 FemmiServ kernel: AMD AuthenticAMD
    May 30 12:30:22 FemmiServ kernel: Hygon HygonGenuine
    May 30 12:30:22 FemmiServ kernel: Centaur CentaurHauls
    May 30 12:30:22 FemmiServ kernel: zhaoxin Shanghai
    May 30 12:30:22 FemmiServ kernel: x86/fpu: x87 FPU will use FXSAVE
    May 30 12:30:22 FemmiServ kernel: BIOS-provided physical RAM map:
    May 30 12:30:22 FemmiServ kernel: BIOS-e820: (mem 0x0000000000000000-0x00000000>
    May 30 12:30:22 FemmiServ kernel: BIOS-e820: (mem 0x000000000009fc00-0x00000000>
    May 30 12:30:22 FemmiServ kernel: BIOS-e820: (mem 0x00000000000e4000-0x00000000>
    May 30 12:30:22 FemmiServ kernel: BIOS-e820: (mem 0x0000000000100000-0x00000000>
    May 30 12:30:22 FemmiServ kernel: BIOS-e820: (mem 0x00000000bf77e000-0x00000000>
    May 30 12:30:22 FemmiServ kernel: BIOS-e820: (mem 0x00000000bf780000-0x00000000>
    May 30 12:30:22 FemmiServ kernel: BIOS-e820: (mem 0x00000000bf78e000-0x00000000>
    May 30 12:30:22 FemmiServ kernel: BIOS-e820: (mem 0x00000000bf7dc000-0x00000000>
    May 30 12:30:22 FemmiServ kernel: BIOS-e820: (mem 0x00000000e0000000-0x00000000>
    May 30 12:30:22 FemmiServ kernel: BIOS-e820: (mem 0x00000000fee00000-0x00000000>
    May 30 12:30:22 FemmiServ kernel: BIOS-e820: (mem 0x00000000ffe00000-0x00000000>
    lines 1-23...skipping...
    -- Logs begin at Sun 2021-05-30 12:30:22 PDT, end at Sun 2021-05-30 12:57:49 PDT. --
    May 30 12:30:22 FemmiServ kernel: microcode: microcode updated early to revision 0xa, date = 2018-
    05-08
    May 30 12:30:22 FemmiServ kernel: Linux version 5.8.0-43-generic (buildd@lcy01-amd64-018) (gcc
    (Ubuntu 9.3.0->
    May 30 12:30:22 FemmiServ kernel: Command line: BOOT_IMAGE=/boot/vmlinuz-5.8.0-43-generic
    root=UUID=42c3d73b->
    May 30 12:30:22 FemmiServ kernel: KERNEL supported cpus:
    May 30 12:30:22 FemmiServ kernel: Intel GenuineIntel
    May 30 12:30:22 FemmiServ kernel: AMD AuthenticAMD
    May 30 12:30:22 FemmiServ kernel: Hygon HygonGenuine
    May 30 12:30:22 FemmiServ kernel: Centaur CentaurHauls
    May 30 12:30:22 FemmiServ kernel: zhaoxin Shanghai
    
    May 30 12:30:22 FemmiServ kernel: x86/fpu: x87 FPU will use FXSAVE
    May 30 12:30:22 FemmiServ kernel: BIOS-provided physical RAM map:
    May 30 12:30:22 FemmiServ kernel: BIOS-e820: (mem 0x0000000000000000-0x000000000009fbff)
    usable
    May 30 12:30:22 FemmiServ kernel: BIOS-e820: (mem 0x000000000009fc00-0x000000000009ffff)
    reserved
    May 30 12:30:22 FemmiServ kernel: BIOS-e820: (mem 0x00000000000e4000-0x00000000000fffff)
    reserved
    May 30 12:30:22 FemmiServ kernel: BIOS-e820: (mem 0x0000000000100000-0x00000000bf76ffff)
    usable
    May 30 12:30:22 FemmiServ kernel: BIOS-e820: (mem 0x00000000bf77e000-0x00000000bf77ffff) type
    9
    May 30 12:30:22 FemmiServ kernel: BIOS-e820: (mem 0x00000000bf780000-0x00000000bf78dfff)
    ACPI data
    May 30 12:30:22 FemmiServ kernel: BIOS-e820: (mem 0x00000000bf78e000-0x00000000bf7dbfff)
    ACPI NVS
    May 30 12:30:22 FemmiServ kernel: BIOS-e820: (mem 0x00000000bf7dc000-0x00000000bfffffff)
    reserved
    May 30 12:30:22 FemmiServ kernel: BIOS-e820: (mem 0x00000000e0000000-0x00000000efffffff)
    reserved
    May 30 12:30:22 FemmiServ kernel: BIOS-e820: (mem 0x00000000fee00000-0x00000000fee00fff)
    reserved
    May 30 12:30:22 FemmiServ kernel: BIOS-e820: (mem 0x00000000ffe00000-0x00000000ffffffff)
    reserved
    May 30 12:30:22 FemmiServ kernel: BIOS-e820: (mem 0x0000000100000000-0x000000043fffffff)
    usable
    May 30 12:30:22 FemmiServ kernel: NX (Execute Disable) protection: active
    May 30 12:30:22 FemmiServ kernel: SMBIOS 2.6 present.
    May 30 12:30:22 FemmiServ kernel: DMI: System manufacturer System Product Name/P7F-E, BIOS
    0303 09/02/2009
    May 30 12:30:22 FemmiServ kernel: tsc: Fast TSC calibration failed
    May 30 12:30:22 FemmiServ kernel: e820: update (mem 0x00000000-0x00000fff) usable ==> reserved
    May 30 12:30:22 FemmiServ kernel: e820: remove (mem 0x000a0000-0x000fffff) usable
    May 30 12:30:22 FemmiServ kernel: last_pfn = 0x440000 max_arch_pfn = 0x400000000
    May 30 12:30:22 FemmiServ kernel: MTRR default type: uncachable
    May 30 12:30:22 FemmiServ kernel: MTRR fixed ranges enabled:
    May 30 12:30:22 FemmiServ kernel: 00000-9FFFF write-back
    May 30 12:30:22 FemmiServ kernel: A0000-BFFFF uncachable
    May 30 12:30:22 FemmiServ kernel: C0000-CBFFF write-protect
    May 30 12:30:22 FemmiServ kernel: CC000-DFFFF uncachable
    May 30 12:30:22 FemmiServ kernel: E0000-E7FFF write-through
    May 30 12:30:22 FemmiServ kernel: E8000-FFFFF write-protect
    May 30 12:30:22 FemmiServ kernel: MTRR variable ranges enabled

$ sudo lshw -C network

*-network
    description: Ethernet interface
    product: 82574L Gigabit Network Connection
    vendor: Intel Corporation
    physical id: 0
    bus info: pci@0000:04:00.0
    logical name: enp4s0
    version: 00
    serial: 90:e6:ba:92:24:94
    size: 1Gbit/s
    capacity: 1Gbit/s
    width: 32 bits
    
    clock: 33MHz
    capabilities: pm msi pciexpress msix bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt
    100bt-fd 1000bt-fd autonegotiation
    configuration: autonegotiation=on broadcast=yes driver=e1000e driverversion=3.2.6-k duplex=full
    firmware=1.8-0 latency=0 link=yes multicast=yes port=twisted pair speed=1Gbit/s
    resources: irq:18 memory:fbce0000-fbcfffff ioport:cc00(size=32) memory:fbcdc000-fbcdffff
    *-network
    description: Ethernet interface
    product: 82574L Gigabit Network Connection
    vendor: Intel Corporation
    physical id: 0
    bus info: pci@0000:05:00.0
    logical name: enp5s0
    version: 00
    serial: 90:e6:ba:92:26:5f
    capacity: 1Gbit/s
    width: 32 bits
    clock: 33MHz
    capabilities: pm msi pciexpress msix bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt
    100bt-fd 1000bt-fd autonegotiation
    configuration: autonegotiation=on broadcast=yes driver=e1000e driverversion=3.2.6-k firmware=1.8-
    0 latency=0 link=no multicast=yes port=twisted pair
    resources: irq:19 memory:fbe00000-fbe1ffff ioport:dc00(size=32) memory:fbdfc000-fbdfffff
    andrew@FemmiServ:~$ ip ro
    default dev enp5s0 scope link metric 1003 linkdown
    169.254.0.0/16 dev enp5s0 proto kernel scope link src 169.254.7.132 linkdown

$ systemctl

     UNIT LOAD ACTIV>
        proc-sys-fs-binfmt_misc.automount loaded activ>
        dev-loop7.device loaded activ>
        sys-devices-pci0000:00-0000:00:1b.0-sound-card0.device loaded activ>
        sys-devices-pci0000:00-0000:00:1c.6-0000:04:00.0-net-enp4s0.device loaded activ>
        sys-devices-pci0000:00-0000:00:1c.7-0000:05:00.0-net-enp5s0.device loaded activ>
        sys-devices-pci0000:00-0000:00:1f.2-ata1-host0-target0:0:0-0:0:0:0-block-sda-sda1.device loaded
        activ>
        sys-devices-pci0000:00-0000:00:1f.2-ata1-host0-target0:0:0-0:0:0:0-block-sda.device loaded activ>
        sys-devices-pci0000:00-0000:00:1f.2-ata1-host0-target0:0:1-0:0:1:0-block-sdb.device loaded activ>
        sys-devices-pci0000:00-0000:00:1f.2-ata2-host1-target1:0:0-1:0:0:0-block-sdc.device loaded activ>
        sys-devices-pci0000:00-0000:00:1f.2-ata2-host1-target1:0:1-1:0:1:0-block-sdd-sdd1.device loaded
        activ>
        sys-devices-pci0000:00-0000:00:1f.2-ata2-host1-target1:0:1-1:0:1:0-block-sdd.device loaded activ>
        sys-devices-pci0000:00-0000:00:1f.5-ata3-host2-target2:0:0-2:0:0:0-block-sde-sde1.device loaded
        activ>
        sys-devices-pci0000:00-0000:00:1f.5-ata3-host2-target2:0:0-2:0:0:0-block-sde.device loaded activ>
        sys-devices-platform-serial8250-tty-ttyS10.device loaded activ>
        sys-devices-platform-serial8250-tty-ttyS11.device loaded activ>
        sys-devices-platform-serial8250-tty-ttyS12.device loaded activ>
        sys-devices-platform-serial8250-tty-ttyS13.device loaded activ>
        sys-devices-platform-serial8250-tty-ttyS14.device loaded activ>
        sys-devices-platform-serial8250-tty-ttyS15.device loaded activ>
        sys-devices-platform-serial8250-tty-ttyS16.device loaded activ>
        sys-devices-platform-serial8250-tty-ttyS17.device loaded activ>
        sys-devices-platform-serial8250-tty-ttyS18.device loaded activ>
        sys-devices-platform-serial8250-tty-ttyS19.device loaded activ>
        sys-devices-platform-serial8250-tty-ttyS2.device loaded activ>
        
        sys-devices-platform-serial8250-tty-ttyS20.device loaded activ>
        sys-devices-platform-serial8250-tty-ttyS21.device loaded activ>
        sys-devices-platform-serial8250-tty-ttyS22.device loaded activ>
        sys-devices-platform-serial8250-tty-ttyS23.device loaded activ>
        sys-devices-platform-serial8250-tty-ttyS24.device loaded activ>
        sys-devices-platform-serial8250-tty-ttyS25.device loaded activ>
        sys-devices-platform-serial8250-tty-ttyS26.device loaded activ>
        sys-devices-platform-serial8250-tty-ttyS27.device loaded activ>
        sys-devices-platform-serial8250-tty-ttyS28.device loaded activ>
        sys-devices-platform-serial8250-tty-ttyS29.device loaded activ>
        sys-devices-platform-serial8250-tty-ttyS3.device loaded activ>
        sys-devices-platform-serial8250-tty-ttyS30.device loaded activ>
        
        andrew@FemmiServ:~$ ps aux |egrep wpa|com
        root 68 0.0 0.0 0 0 ? S May30 0:00 (kcompactd0)
        root 686 0.0 0.0 13688 4880 ? Ss May30 0:00 /sbin/wpa_supplicant -u -s -O
        /run/wpa_supplicant
        andrew 1414 0.0 0.1 282780 29756 ? Ssl May30 0:00 /usr/libexec/gsd-wacom
        andrew 14511 0.0 0.0 17672 724 pts/0 S+ 15:04 0:00 grep -E --color=auto wpa|com
        andrew@FemmiServ:~$ sudo tcpdump -v
        tcpdump: listening on enp4s0, link-type EN10MB (Ethernet), capture size 262144 bytes
        15:13:07.192454 IP (tos 0x0, ttl 1, id 50360, offset 0, flags (none), proto UDP (17), length 202)
        50.39.173.111.51922 > 239.255.255.250.1900: UDP, length 174
        15:13:08.206626 IP (tos 0x0, ttl 1, id 50361, offset 0, flags (none), proto UDP (17), length 202)
        50.39.173.111.51922 > 239.255.255.250.1900: UDP, length 174
        15:13:09.208272 IP (tos 0x0, ttl 1, id 50362, offset 0, flags (none), proto UDP (17), length 202)
        50.39.173.111.51922 > 239.255.255.250.1900: UDP, length 174
        15:13:10.213948 IP (tos 0x0, ttl 1, id 50363, offset 0, flags (none), proto UDP (17), length 202)
        50.39.173.111.51922 > 239.255.255.250.1900: UDP, length 174
        15:13:11.108123 ARP, Ethernet (len 6), IPv4 (len 4), Request who-has 192.168.144.200 (Broadcast) tell
        0.0.0.0, length 46
        15:13:17.128842 ARP, Ethernet (len 6), IPv4 (len 4), Request who-has 192.168.144.200 (Broadcast) tell
        0.0.0.0, length 46
        15:13:23.149624 ARP, Ethernet (len 6), IPv4 (len 4), Request who-has 192.168.144.200 (Broadcast) tell
        0.0.0.0, length 46
        15:13:28.638930 IP (tos 0xc0, ttl 64, id 0, offset 0, flags (DF), proto UDP (17), length 321)
        0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from 90:e6:ba:92:24:94 (oui
        Unknown), length 293, xid 0xaa2ba215, secs 836, Flags (none)
        Client-Ethernet-Address 90:e6:ba:92:24:94 (oui Unknown)
        Vendor-rfc1048 Extensions
        Magic Cookie 0x63825363
        DHCP-Message Option 53, length 1: Discover
        Client-ID Option 61, length 7: ether 90:e6:ba:92:24:94
        Parameter-Request Option 55, length 17:
        Subnet-Mask, Time-Zone, Domain-Name-Server, Hostname
        Domain-Name, MTU, BR, Classless-Static-Route
        Default-Gateway, Static-Route, YD, YS
        NTP, Option 119, Classless-Static-Route-Microsoft, Option 252
        RP
        MSZ Option 57, length 2: 576
        Requested-IP Option 50, length 4: 192.168.254.24
        Hostname Option 12, length 9: "FemmiServ"
        15:13:29.170117 ARP, Ethernet (len 6), IPv4 (len 4), Request who-has 192.168.144.200 (Broadcast) tell
        0.0.0.0, length 46
        15:13:35.190450 ARP, Ethernet (len 6), IPv4 (len 4), Request who-has 192.168.144.200 (Broadcast) tell
        
        0.0.0.0, length 46
        15:13:41.212982 ARP, Ethernet (len 6), IPv4 (len 4), Request who-has 192.168.144.200 (Broadcast) tell
        0.0.0.0, length 46
        15:13:47.231609 ARP, Ethernet (len 6), IPv4 (len 4), Request who-has 192.168.144.200 (Broadcast) tell
        0.0.0.0, length 46
        15:13:53.251508 ARP, Ethernet (len 6), IPv4 (len 4), Request who-has 192.168.144.200 (Broadcast) tell
        0.0.0.0, length 46
        15:13:59.271474 ARP, Ethernet (len 6), IPv4 (len 4), Request who-has 192.168.144.200 (Broadcast) tell
        0.0.0.0, length 46
        15:14:05.290307 ARP, Ethernet (len 6), IPv4 (len 4), Request who-has 192.168.144.200 (Broadcast) tell
        0.0.0.0, length 46
        ^C
        15 packets captured
        15 packets received by filter
        0 packets dropped by kernel

$ sudo tcpdump -n udp port 68 -vv

tcpdump: listening on enp4s0, link-type EN10MB (Ethernet), capture size 262144 bytes
    15:17:46.522511 IP (tos 0xc0, ttl 64, id 0, offset 0, flags (DF), proto UDP (17), length 321)
    0.0.0.0.68 > 255.255.255.255.67: (udp sum ok) BOOTP/DHCP, Request from 90:e6:ba:92:24:94,
    length 293, xid 0xf259977b, secs 1094, Flags (none) (0x0000)
    Client-Ethernet-Address 90:e6:ba:92:24:94
    Vendor-rfc1048 Extensions
    Magic Cookie 0x63825363
    DHCP-Message Option 53, length 1: Discover
    Client-ID Option 61, length 7: ether 90:e6:ba:92:24:94
    Parameter-Request Option 55, length 17:
    Subnet-Mask, Time-Zone, Domain-Name-Server, Hostname
    Domain-Name, MTU, BR, Classless-Static-Route
    Default-Gateway, Static-Route, YD, YS
    NTP, Option 119, Classless-Static-Route-Microsoft, Option 252
    RP
    MSZ Option 57, length 2: 576
    Requested-IP Option 50, length 4: 192.168.254.24
    Hostname Option 12, length 9: "FemmiServ"
    15:18:50.758747 IP (tos 0xc0, ttl 64, id 0, offset 0, flags (DF), proto UDP (17), length 321)
    0.0.0.0.68 > 255.255.255.255.67: (udp sum ok) BOOTP/DHCP, Request from 90:e6:ba:92:24:94,
    length 293, xid 0x355ce1b5, secs 1158, Flags (none) (0x0000)
    Client-Ethernet-Address 90:e6:ba:92:24:94
    Vendor-rfc1048 Extensions
    Magic Cookie 0x63825363
    DHCP-Message Option 53, length 1: Discover
    Client-ID Option 61, length 7: ether 90:e6:ba:92:24:94
    Parameter-Request Option 55, length 17:
    Subnet-Mask, Time-Zone, Domain-Name-Server, Hostname
    Domain-Name, MTU, BR, Classless-Static-Route
    Default-Gateway, Static-Route, YD, YS
    NTP, Option 119, Classless-Static-Route-Microsoft, Option 252
    RP
    MSZ Option 57, length 2: 576
    Requested-IP Option 50, length 4: 192.168.254.24
    Hostname Option 12, length 9: "FemmiServ"
    ^C
    2 packets captured
    2 packets received by filter
    0 packets dropped by kernel