Ok so of course I have googled several sources
ie http://www.coffer.com/mac_info/locate-unix.html

and they usually suggest entering the following in the terminal

$ifconfig -a

However in the returned results I don't see eth0 or HWaddr.

Can anyone help?

If I go to System>Preferences>Internet & Network>Network Connections

and then select the Ethernet TAB

I do see a Device entry with 2 different addresses toggled with a select drop down.
One starts with eno1 and the other with enp5s0

and then under that an empty entry for 'Cloned MAC address'

I realize 'ifconfig -a' isn't showing 'eth0' but try

and see what comes up.

EDIT:

OP's interfaces weren't in their original question. Likewise for my second reply. I didn't refresh before posting.

Also, are you sure your wired connection is active? How are you connected right now?

I use the command ip link:
The MAC address is 00:1e:06:11:20:10 after link/ether.
I am running Ubuntu 16, but you should have the same result on 18.

ipconfig -a does output HWaddr. However, your interface is not called eth0. You seem to have two interfaces named eno1 and enp5s0. Ubuntu now uses so-called predictable interface names. For example, enp5s0 is the interface in PCI bus 5, slot 0.

If this doesn't help you, I suggest you share the output of the two commands, ip link and ifconfig -a.

Thanks!!

So can I assume that Device eno1 (in Network Connections preferences) points to my MAC address?

Here is my output

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: enp5s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP mode DEFAULT group default qlen 1000
link/ether 10:7b:44:92:72:8d brd ff:ff:ff:ff:ff:ff
3: wlp4s0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 4000
link/ether dc:ef:ca:fa:37:65 brd ff:ff:ff:ff:ff:ff
4: wlp3s0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
link/ether e0:4f:43:70:a2:72 brd ff:ff:ff:ff:ff:ff




enp5s0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.1.5 netmask 255.255.255.0 broadcast 192.168.1.255
inet6 fe80::bee2:581c:41b0:2568 prefixlen 64 scopeid 0x20<link>
ether 10:7b:44:92:72:8d txqueuelen 1000 (Ethernet)
RX packets 74842 bytes 30044281 (30.0 MB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 25676 bytes 3492535 (3.4 MB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
device memory 0xef700000-ef71ffff

lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 1000 (Local Loopback)
RX packets 6097 bytes 1288647 (1.2 MB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 6097 bytes 1288647 (1.2 MB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

wlp3s0: flags=4098<BROADCAST,MULTICAST> mtu 1500
ether e0:4f:43:70:a2:72 txqueuelen 1000 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

wlp4s0: flags=4098<BROADCAST,MULTICAST> mtu 1500
ether dc:ef:ca:fa:37:65 txqueuelen 4000 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

You should be able to find the info you wanted now. Also, if I were you I would remove any 'sensitive' information from the output you posted. Maybe I'm just paranoid though :P

EDIT:

This reply was in response to post #5 which at the time only included the output of ifconfig and ip link.

No.

First, I don't see eno1 in your output. I see enp5s0 and two wireless interfaces. I don't know why the Network Preferences tool reports eno1.

Second, there is no such thing as "my MAC address". Each interface has its own MAC address. You have three interfaces, therefore three MAC addresses.

To prevent confusion: I exclude the loopback interface; it's listed as having MAC address 00:00:00:00:00:00, but it only exists inside the kernel and doesn't correspond to a real interface.

FYI there is no security risk in posting private IP addresses or their MAC. There are probably millions of home routers that default to 192.168.1.0/24 private network. A LAN MAC is not accessible from the internet and can not be used by anyone to gain access as far as I know.

I missed what was edited in post #5 so nevermind...

1 members found this post helpful.

Interesting. My knowledge in this area is limited. In the past I've received help in forums from members with a lot more experience and knowledge than me who wouldn't post this info and generally advised against it. Some blogs, etc, that I've read also said to block out this info. So, since I haven't really had the opportunity to study this area I decided to air on the side of caution. I mean if I don't post it I don't have anything to lose or worry about, right?

michaelk, thanks. That was my concern before posting as well.

berndbausch, thanks. As mentioned eno1 is visible in my Network Connections preferences

Based on above now I'm guessing the first or enp5s0 points to a primary interface and 10:7b:44:92:72:8d is the MAC address I want?

I should clarify first why I need the MAC address. It is required for a software license at the time of purchase.

I don’t think that there is such a thing as a “primary interface”, but it’s true that enp5s0 has the lowest index number. Perhaps the documentation for the application you are about to buy explains what to do if there are several MAC addresses.

While it may not have anything to do with the question, it’s puzzling that ip link or ifconfig don’t list eno1. Do you have more than one wired interface?