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Questions tagged [mac-address]

The MAC address is the network address of an interface at data link layer in IEEE 802 networks such as ethernet.

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How to disable MAC address randomization in Fedora 40?

I upgraded to Fedora 40 and was introduced to its new feature of MAC address randomization (for Wi-Fi interfaces at least). How do I disable it? Links I found didn't work for me: https://discussion....
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Debian 12 – All of a sudden my USB3 LAN adapter gets assigned random MAC address at each reboot

I have various small NUCs with attached on each one some of this USB3 LAN adapters (because the NUCs have only one Ethernet, so I added extra ones with USB3 adapters). You can see an image of the ...
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Linux networking bridge not forwarding manually created packet

I am trying to implement packet forwarding using a BPF-program. The idea is to forward a suitable packet from veth1 (ingress) directly to veth2 (egress). The problem I am facing is that the redirected ...
Dan23's user avatar
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Machine MAC address with Ubuntu on top of WSL2

Running Ubuntu 22.04.3 LTS on top of WSL2 Output of ifconfig: eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1492 inet 172.28.193.11 netmask 255.255.240.0 broadcast 172.28.207.255 ...
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3 answers
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How to find unspoofed MAC address of NIC

In Red Hat Enterprise Linux (RHEL) 8, if someone does ifconfig eth0 hw ether abcd12341234, all I know is ifconfig and ip -a, so then is there a way to reliably get the real MAC address of that eth0 ...
ron's user avatar
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Nftables to do scalable MAC translation in NAPT-style

I'm a networking senior guy steadily diving more into Linux internals over last 5 years, grasping networking caps a lot, however just arriving at Netfilter domain and learning of nftables last 3-4 ...
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How do I get all MAC addresses of all devices on my LAN that have an IP address (equivalent of doas nmap -sn but for IPv6)?

#!/usr/bin/bash echo "Give me your private IP and its mask";read given if [[ "$given" =~ ^([0-9]{1,3}\.){3}[0-9]{1,3}/{0,1}[0-9]{1,3} ]]; then echo "version 4" ...
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How is my _gateway ARP entry address resetting itself to a "hardcoded" value?

I've got an ubuntu linux PC on a private 192.168.x.y LAN. It's got an IP on the 0 subnet (192.168.0.y) and is able to ping other PC's on the 0 subnet. It looked like the _gateway MAC address had been ...
LukeDev's user avatar
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Print entire 802.11 WiFi Ethernet frame header with tcpdump (or anything else)

I'm currently learning about WiFi Ethernet frames and want to sniff raw ethernet traffic from my laptop's WiFi adapter. Running sudo tcpdump -vvv -n -i wifi0 -e prints something like the following: ...
Some Name's user avatar
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What is the command to get the wifi name of a BSSID device in Kali Linux?

I only have the BSSID of the specific target device I want to connect to. How can I determine the actual Wi-Fi network name that the device is connected to? I'm using kali linux, and I used crunch 8 ...
Irene's user avatar
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2 answers
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How are USB devices uniquely distinguished?

For experimentation purposes I have bought some pairs of wifi and bluetooth devices and I plan to get some more. However when two or more of the same type are plugged in to the hub lsusb lists ...
vfclists's user avatar
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2 votes
1 answer
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USB LTE modem without MAC address?

I'm connecting a linux machine using a nowadays popular Huawei Brovi E3372-325 LTE USB Stick to the internet. The special requirement is that incoming ssh/ping/NTP/... connections must reach my linux ...
gorogm's user avatar
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macchanger's effect disappears when wifi connection is back up

When I installed macchanger package I set it to change mac address everytime an interface is down. However I noticed that my IP address was not changing. So I examined my mac address. When connected ...
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How do I set a static MAC address for the default gateway on startup?

I need to set the default gateway's MAC address statically. I used the command: arp -s <ip> <mac> That works, but on reboot the entry is back to being dynamic. I have tried: Writing the ...
randmon's user avatar
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How to tell qemu to randomly assign MAC addresses

I'm starting three Qemu VMs, each with several network interfaces. The network interface config looks like this: -nic user,hostfwd=tcp::"${ssh_ports[$machine]}"-:22,model=virtio-net-pci \ -...
jan's user avatar
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How can I make Linux generate different MAC addresses for different bridge devices which are on different PCs?

I have just upgraded two servers from Debian 10 (Buster) to Debian 11 (Bullseye). Afterwards, I could not reach either of them via the network any more. After some investigation, the following problem ...
Binarus's user avatar
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1 vote
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Find out what keeps changing my MAC address on reboot

Some time ago I installed macchanger to play around with some wifi stuff. Soon after that I uninstalled it again (with giving 'purge' to apt), together with everything else I installed before around ...
Jaleks's user avatar
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Why did the mac address of bond changed on CentOS7 after reboot

I have two interfaces bonded together in LACP mode (mode=4 <=> 802.3ad) in bond0 : The mac address of bond0before reboot : $ cat /sys/class/net/bond0/address xx:xx:xx:xx:xx:bf The mac address ...
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MAC based routing with nftables and ipv6

I want to match every traffic from a server but it is at the same interface. MAC 88:7e:25:d3:90:0b > ens19 > table 147 Therefore I made this nftables rule table ip filter { # handle 3 chain ...
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818 views

Unique Mac address for Secondary IP address?

Using one Ubuntu machine with one physical NIC, I want to make it seem that there are two or more additional machines on my real network, all controlled by this one Ubuntu machine. For example, I have ...
Andrew Campi's user avatar
1 vote
1 answer
860 views

maching source MAC address in nftables

I want to match all data from ens19 with the mac address 88:7e:25:d3:90:0b use table 147. My idea is to mark the data from 88:7e:25:d3:90:0b and give it a fwmark 14. Then use ip rule to the specified ...
zhihuiyuze's user avatar
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Why is this MAC address iptables whitelisting not working?

This is on a router. I have $mac as the MAC of one client and $set is an ipset of type hash:net. My intention is to deny access to all networks in $set, except for $mac who can access the networks. -A ...
user536142's user avatar
1 vote
1 answer
495 views

Get MAC address before network is ready

I created a script to set a bunch of computer hostnames to the last 8 digits of the MAC address. The MAC address is a unique number baked into every computer, so it works well. I created a systemd ...
run_the_race's user avatar
1 vote
0 answers
509 views

What caused the ethernet mac address to change after an update of my linux system?

I recently updated my machine and after a reboot I discovered that my ethernet mac address had changed. The router settings for that machine were no longer implemented as it was viewed as a different ...
ram's user avatar
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2 answers
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Bridge gets random MAC instead of port address

I have a fresh install of Debian 11 and did a bridge setup: auto br0 iface br0 inet dhcp bridge_ports eno1 What I expect is that br0 has the same MAC address as eno1 but it gets a randomly ...
AlexD's user avatar
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1 answer
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Run a terminal command when device connects to a WiFi network

I spoof my MAC address on a public WiFi network that I use often, but I do not want to have my MAC spoofed on my home network. I was thinking that a way to automate this is to have the computer ...
SteepAtticStairs's user avatar
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1 answer
197 views

Delete illegal router from network

I have a default gateway with IP address 192.168.1.1 and MAC address 5c:77:76:6e:0d:7b. It is my only wi fi modem router from which I receive internet. But in input nftables logs I saw another one ...
Tina's user avatar
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how do i get interface name, ip and mac from active interface only (except lo)

I use this command to get the name of my network interfaces and their mac address ip -o link | awk '$2 != "lo:" {print $2, $(NF-2)}' | sed 's_: _ _' out: enp2s0 XX:XX:XX:XX:XX:XX wlp1s0 YY:...
acgbox's user avatar
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1 answer
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Loop through MAC addresses, how to handle both numbers (0-9) and letters (a-f) in a "for" loop

I've a script with this code for i in {2..9} do grep "Node${i}\|01, source address = 00:00:00:00:00:0${i}" t1.txt > t2.txt done Is it possible to expand the loop ...
tesiman's user avatar
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How to filter (rate-limit) traffic through a bridge, using nftables, depending on whether or not the traffic originated locally?

I'd appreciate some help with understanding how traffic filtering in a bridge works, especially for packets / Ethernet frames which originated locally. To explain the problem, I'll shortly describe ...
Binarus's user avatar
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Network driver didn't actually change to the new MAC

whenever I try to change my MAC address I get "Network driver didn't actually change to the new MAC!!" error. I have tried; macchanger wlan0 down macchanger -r wlan0 Output: Current MAC: ...
Turhan Ergene's user avatar
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67 views

MAC address spoof of a wifi connected device, not the network interface of the PC

Some devices are known to data hosts by their MAC. If you physically replace that device and it has a new MAC the host will not accept the data. All the router will do is spoof the network interface ...
Jim Baker's user avatar
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270 views

Detecting IP/MAC spoofing using iptables

Is there any way to detect IP or MAC address spoofing with iptables?
Meysam's user avatar
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359 views

Unable to connect via SSH to when eth0 is disconnected

I've seen a few similar questions, to this one, but have not found a solution. I'm working on a Raspberry Pi and wiring up a second Ethernet port (ultimately it will be the only port on a Pi Zero, ...
JStroop's user avatar
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1 answer
909 views

Read MAC using Buildroot 20.20 NVMEM_IMX_OCOTP on i.MX7s

We are migrating from Buildroot 2018.02.9 (linux-4.14.85) to Buildroot 2020.02.2 (linux-5.4.40), and have found that we can no longer read the MAC address on an I.MX7s SoC. The following indicates why:...
Geoff's user avatar
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18 votes
7 answers
3k views

Find the IP address of a newly-booted Raspberry Pi

I've attached a Raspberry Pi running Ubuntu to my home network with a cable. It is booted up and connected to the network. The Pi has no keyboard, mouse, or monitor. If I know the IP address that was ...
pitosalas's user avatar
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1 vote
1 answer
187 views

How to find where zoom is getting MAC

It looks like based on stdout output after running a malicious app called zoom, that it gathers the currently used MAC Address. I am looking to block this functionality via AppArmor, however I cant ...
john doe's user avatar
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1 answer
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Changing of MAC Address with Network Manager on Debian 10

Looking at syslog files on Debian 10 form a previous session I have noticed a MAC Address change and I do not know why it is happening. Any ideas on how to stop this? Jun 8 15:43:46 NetworkManager[...
nemi's user avatar
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1 vote
1 answer
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mac address of usb ethernet device changes each time on reboot on raspberry pi 3b running raspbian

Mac address of embedded usb ethernet device (smsc95xx driver) is being changed on each reboot - its happening despite adding to the /boot/cmdline.txt smsc95xx.macaddr=00:11:22:33:45:67 - I know that ...
ciekawy's user avatar
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1 answer
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Does a DHCP server assign MAC addresses to network computers?

I have been working on basic Linux network configuration. I am aware that IP addresses, default gateways, subnetmasks etc are assigned by a DHCP server but am unsure if MAC addresses are assigned by ...
Stewart Bovis's user avatar
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1 answer
493 views

How can I change the mac address on a Linux 3.3.8 device without macchanger?

I'm trying to permanently modify my MAC address on a device running Linux 3.3.8 I cannot get macchanger to install either. When I try it with ifconfig eth0 hw ether I get ifconfig: SIOCSIFHWADDR:...
Febian Shah's user avatar
1 vote
1 answer
2k views

Macchanger works until connecting to network in Debian 10 [duplicate]

I’ve been trying to test out my MAC spoofing abilities on my home network using Macchanger. When not connected to WiFi, it works just fine. I can bring the interface down using ifconfig, change the ...
ztaylor's user avatar
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4 votes
1 answer
3k views

SSH with MAC based filtering using iptables - recommended?

I have a server in an internal network (login there via VPN) from where I login to the server via SSH with OpenSSH public/private key authentication. From a security point of view, I want to tie the ...
Ferit's user avatar
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0 votes
2 answers
38 views

Can I remotely connect my office system "PC-A" to another neighbouring office system "PC-B" through mac address?

System description I have two Ubuntu (Mate-flavour) systems in my office "PC-A" and "PC-B". previously(4 days ago) I was able to remotely connect both the PC from home. both are connected with the ...
sai's user avatar
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1 answer
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Changing `iptables` rules by `MAC` address

I'm using a gateway connected to VPN to do forwarding with the port of an industrial LAN element. I use iptables forwarding to access port 80/443 of my gateway in the browser to show me the contents ...
Fco Javier Balón's user avatar
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0 answers
59 views

Pinging default gateway on a Linux virtual machine

I have two question about the network. I started to ping my router from my Linux virtual machine and I have intercepted these ICMP frames. I noticed that the destination MAC address is not my router ...
Bartosz Sochacki's user avatar
0 votes
1 answer
38 views

Upgrading stretch to buster interface MAC issues

After upgrading Debian from stretch to buster I am encountering weird behaviour of the ethernet interface. This installation runs on a Hyper-V host. After rebooting, the mac address reported by the ...
atapaka's user avatar
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0 votes
1 answer
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How to change eth0 MAC address only using a text editor?

I am running OpenWrt (=Busybox per SSH) so my amount of binaries is limited. I would like to change my MAC address only using a text editor like nano.
Sir Muffington's user avatar
1 vote
2 answers
1k views

Is it necessary to down/up interface during MAC address change?

I'm using SuSE 12.2 with custom kernel 4.4.21 (minor changes related to real time environment). Is it really necessary to down/up the interface during the MAC address change? What I observed is that ...
saleph's user avatar
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-1 votes
1 answer
347 views

Attempting to use airmon-ng returns error

So im trying to use airmon-ng so i can get some mac addresses and deauth them 'with permission, ofc' im on Nethunter and airmon returns this ls: cannot access '/sys/class/net': No such file or ...
CodeWritten's user avatar