34
votes
How to view your computer's MAC address using 'ifconfig'?
First, your computer doesn't have a MAC address. Each network card has a MAC address. So if your machine has a wireless card and an Ethernet card, it'll have two MAC addresses.
On Linux, either of ...
- 30.4k
32
votes
Accepted
Why assign MAC and IP addresses on Bridge interface
Because a bridge is an ethernet device it needs a MAC address. A linux bridge can originate things like spanning-tree protocol frames, and traffic like that needs an origin MAC address.
A bridge ...
- 36.5k
24
votes
Find the IP address of a newly-booted Raspberry Pi
Assuming not too large a network range you can force the ARP table to be populated before you look through it. These examples are for a typical home network on 192.168.1.0-255
nmap -sn 192.168.1.0/24 ...
- 120k
23
votes
Accepted
How to find unspoofed MAC address of NIC
This answer is about Linux.
ifconfig is obsolete and doesn't have access to a kernel API able to provide it this information.
This information has been able to be retrieved for a long time with ...
- 37.5k
17
votes
Accepted
How to stop MAC address from changing after disconnecting?
NetworkManager will reset your MAC address during the Wi-Fi scanning.
To permanently change your MAC address:
Edit your /etc/NetworkManager/NetworkManager.conf as follows:
[main]
plugins=ifupdown,...
- 67.8k
15
votes
Why assign MAC and IP addresses on Bridge interface
The bridge device listed with your other networking devices does not represent the virtual bridge, it represents a virtual NIC that is connected to the bridge. If you had a physical bridge connected ...
- 141
15
votes
How to find unspoofed MAC address of NIC
This answer is about NICs in general.
Nothing about that MAC address is "unreal". In general, nothing guarantees that any network card does have any ROM that contains a unique MAC address. ...
- 34.5k
14
votes
Why assign MAC and IP addresses on Bridge interface
Yes, the bridge interface acts as an additional port.
After man 5 systemd.netdev:
A bridge device is a software switch, and each of its slave devices and the bridge itself are ports of the switch.
- 257
13
votes
How to view your computer's MAC address using 'ifconfig'?
For many linux systems ipconfig doesn't show the mac anymore. If that is the case for you, try:
ip -a link
- 371
10
votes
Accepted
How to view your computer's MAC address using 'ifconfig'?
The command that you want on MacOS, FreeBSD, and TrueOS is:
ifconfig -a link
OpenBSD's ifconfig doesn't have this.
Further reading
ifconfig. Mac OS 10 Manual Pages. Apple corporation. 2008.
...
- 69.9k
8
votes
Find the IP address of a newly-booted Raspberry Pi
This is an indirect but sufficient answer. I realized that if I know the hostname for the Raspberry Pi then I can use ssh [email protected]. That worked.
- 637
8
votes
Accepted
Loop through MAC addresses, how to handle both numbers (0-9) and letters (a-f) in a "for" loop
Just add another brace expansion for the letters:
for i in {2..9} {a..f}
do
grep "Node${i}\|01, source address = 00:00:00:00:00:0${i}" t1.txt > t2.txt
done
Note that this is likely ...
- 245k
7
votes
Accepted
How can I make Linux generate different MAC addresses for different bridge devices which are on different PCs?
Browsing in Internet I found this bug report on systemd-udev related to Debian 11 bridges: systemd-udev interferes with MAC addresses of interfaces it's not supposed to do
#21185:
ash.in.ffho.net:~# ...
- 37.5k
7
votes
How to find unspoofed MAC address of NIC
This answer is specific to FreeBSD.
The MAC addresses of the NICs that were identified during the most recent boot are recorded in /var/run/dmesg.boot:
$ grep 'Ethernet' /var/run/dmesg.boot
em0: ...
- 8,322
6
votes
Accepted
Change MAC address of network interface on lower level
Background
/proc and /sys filesystems are just a view of kernel structures, both filesystems reside in memory. Although both filesystems are writable (well, some of the files in there are writable) ...
- 8,727
6
votes
Accepted
FreeBSD static ARP entry when link cycles
Becoming friends with FreeBSD
You seem to be on a partially correct path. I presume you have a lot of knowledge on Unix but not so much an actual FreeBSD system. The reason I am guessing this is you ...
- 3,484
6
votes
Accepted
Delete illegal router from network
Routers often have multiple virtual network interfaces, and the MAC address that gets assigned to these is made by flipping some bits of the hardware MAC address.
So the "illegal router" you ...
- 32.7k
5
votes
Accepted
How to find MAC address on RHEL 7.3?
The command ip link shows the MAC address on all interfaces.
- 13.3k
5
votes
How to view your computer's MAC address using 'ifconfig'?
Instead of using ifconfig, you can use ip command.
ip -brief link will show following output.
lo UNKNOWN 00:00:00:00:00:00 <LOOPBACK,UP,LOWER_UP>
enp1s0 DOWN ...
- 181
5
votes
Accepted
Forcing HWADDR to correct itself in ifcfg-eth0 network script on boot CentOS 7
The easiest solution is probably to disable the "predictable device naming" behavior by setting the following options on your kernel command line:
biosdevname=0 net.ifnames=0
With this in place, the ...
- 36.5k
5
votes
Command-line tool to obtain OUI vendor info from MAC address?
Cross-Distro Fully Automated Solution:
The following script automates the process and works across all Linux distros because it has no dependencies on specialized packages. It simply parses the ...
- 2,614
5
votes
Add vlan to interface with unique mac - different syntax for different Linux distros
You can assign VLAN MAC address with ip command:
# ip link add link <interface> name <vlan interface name> address <mac> type vlan id <vlan ID>
Example:
# ip link add link ...
- 1,396
5
votes
How to stop MAC address from changing after disconnecting?
If other methods cannot solve the problem, you can try to edit /etc/NetworkManager/conf.d/30-randomize-mac-address.conf
[connection-mac-randomization]
ethernet.cloned-mac-address=permanent
wifi.cloned-...
- 51
5
votes
Does `ifconfig` show the MAC address of a network interface following `ether`?
Note that different implementations of ifconfig report data in different ways.
For the net-tools version typically found on Linux, the word ether is the hardware class, and the value following that ...
- 46.3k
5
votes
Find the IP address of a newly-booted Raspberry Pi
Disclaimer: I am the author of this tool.
Try this tool, written for this exact purpose. It currently runs on Windows. It listens to traffic on the network and lists hosts that come up, such as your ...
- 159
5
votes
Accepted
USB LTE modem without MAC address?
If I'm not mistake, I don't use RNDIS right now.
RNDIS is a Windows-specific network interface driver API. Um, that as nothing to do with what you're doing, right?
What might be the reason, that ...
- 34.5k
4
votes
Change MAC address of network interface on lower level
By changing your MAC address at a higher level, for instance using Network Manager, you are not changing the physical MAC address. You are "spoofing" the system, linking the physical MAC to the one ...
- 151
4
votes
Why assign MAC and IP addresses on Bridge interface
The br0 and virbr0 interfaces listed by ip addr and ip link are tap interfaces that connect the host to the br0 bridge and virbr0 bridge respectively. This overloading of names can certainly be ...
- 41
Only top scored, non community-wiki answers of a minimum length are eligible