A Media Access Control address (MAC address) is a unique identifier assigned to network interfaces for communications on the physical network segment.

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7answers
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What's a good way to handle multiple devices with the same MAC address on one network?

The devices I'm working with come off the production line all set to the same MAC address. I can set each one to have their own static IP, and I'm wondering if there would be a way to connect them to ...
3
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1answer
277 views

Gather mac addresses of domain computers, preferably from command line

In preparing to move to a domain and SCCM to manage machines in a new office I need to gather their MAC addresses. I could go from machine to machine, run ipconfig and gather the ip, but that would ...
2
votes
1answer
1k views

Why are eth0 and vmbr0 (bridge) having the same MAC addresses?

I configured my Debian (with KVM on board) as following: /etc/network/interfaces: auto lo iface lo inet loopback auto eth0 iface eth0 inet manual auto vmbr0 iface vmbr0 inet static address ...
2
votes
2answers
424 views

Any standard protocol to find all systems' MAC addresses and possible hostname connected to a switch

I have servers and storage arrays in a composite lab and intermediate switches. I want to get a list of all the MAC addresses of the systems connected to each switch. It should be switch vendor ...
2
votes
2answers
4k views

iptables, allow access from certain MAC addresses

Presently, I limit which clients can access my server by using IP addresses via iptables, only approved IP addresses can connect. However, the problem with this is if a client is on a laptop and goes ...
0
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3answers
3k views

Linux: find MAC Address for unconfigured card

I have a linux system for which I want to create my own udev rules for the nic. Currently there are no rules, so no ethX is configured. I can't do ifconfig (it is not showing any interfaces besides ...
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1answer
55 views

Server 2003 Filter mobile devices via MAC

At one of my client's sites I need to keep my users unauthorized devices off the wireless. They all know the SSID and Password because many of them have laptops that need the wireless. I'm running ...
0
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1answer
568 views

Juniper networks mac addresses of switches in a LAN

I have a LAN consisting of switches connected to each other then to some devices, How to get the mac address of the switch connected to a specific port on the main switch then get the ports and device ...
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2answers
1k views

Show mac-address table on custom interface in FreeBSD and Linux [closed]

On switches I can show mac addresses on any port by "show mac-address-table port X" Is there any way to do this on FreeBSD and Linux systems?
3
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1answer
3k views

Hyper-V MAC Address collisions

I am trying to troubleshoot a performance issue with our application on a customer network. We do not support the network infrastructure, and the people that do have effectively washed their hands of ...
3
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1answer
505 views

Windows Server 2008 ARP Cache Poisioning

Recently ran into a very strange problem. Several applications were having issues communication through our F5 Load-Balancer. When we looked into it we found that the router had an incorrect ARP and ...
1
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1answer
358 views

Redirect traffic on port 80 into apache for unknown macs, and into squid for some macs

I have a linux box behaving like a router that handles two network interfaces: eth0 for internet and eth1 for LAN. I set up iptables in order to redirect all the web traffic coming by the LAN into a ...
0
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1answer
70 views

Possible MAC conflict in ESX

I have two virtual machines that are 10.1.1.10 and 10.1.1.20 in an ESX. I try to access theses machines by another network 192.168.1.0/24. The problem is that when I can ping one machine, I can not ...
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1answer
502 views

Broadcom NetXtreme II GigE Teaming Does Not Use Unique MAC, Causing Collisions

I currently have a new Dell server on my local (inside) network that I have setup to use three of the four nics to create a team. Examples below. NIC_1 - mac: 000000000001 - ip: n/a NIC_2 - mac: ...
-1
votes
2answers
129 views

MAC Addresses (in devices) [closed]

In what type of hardware are MAC addresses used besides routers? For example, could a MAC address be in printer or in a mobile phone? Yes, I am talking about Ethernet MAC addresses. Can you please ...
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vote
4answers
2k views

Cisco Switch: trigger mac-address table update

If I run show mac-address-table dynamic I get a bunch of mac addresses on that table. But due to the aging parameter, I don't see the mac addresses of all possible devices on the network that come ...
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votes
1answer
867 views

Same MAC but different IP on router [closed]

If a device has same mac address but different IP on home router, is this some sort of error or hacking? What is going on? I can't attach a pic so I've listed below. Computer name for second doesn't ...
-1
votes
2answers
462 views

clone ip and mac addr on wlan

what will happen if i clone another pc on a wlan network? consider the following scenario. PC1(victim) mac1 ip1 PC2(attacker) mac2 ip2. I set mac2 = mac1 and ip2 = ip1 i ran the following ...
2
votes
2answers
735 views

Solaris doesn't know which MAC address to use to send an UDP multicast message

I have a pair of Solaris 10 boxes which are supposed to send multicast UDP packets to a group of hosts. One of them works just fine, whereas the other one does not. The problem with the second ...
0
votes
1answer
447 views

Switch CAM table and ARP messages

When the switch CAM table is empty and it receives an ARP message, does it add to the CAM table the source MAC address ? In Packet Tracer I saw that it does add it, but I read in some book that the ...
2
votes
3answers
11k views

Duplicate MAC address on the same LAN possible?

Let's say someone is on the same network as me and spoofs their MAC address to match mine: Is this possible? Can two or more clients with the same MAC address be on the same network at the same time ...
2
votes
1answer
521 views

Cisco switch:change mac type from dynamic to static in console

How to change mac from static to dynamic in mac-address-table (switch)?I find this official source but still not understand what options I must choose. Something like this: switch(config)# ...
-1
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1answer
93 views

how to block mac address with portsentry

I use portsentry to block ip address who trying to scanning. Now how do I want to block mac address who trying to scanning. Can I use portsentry, or possibly other tools?
2
votes
4answers
481 views

Newbie questions on MAC and high availability failovers

I am reading about High Availability and I can not understand the following I read: On failover the primary IP migrates to the backup server BUT so must the MAC address. Specifically I read that ...
2
votes
1answer
122 views

MAC and IP address text-identicon as avatar

I would like to create something like identicons but not with images but with a unique word for each IP-Addresses and MAC-Addresses. create an easy to remember alias for a mac address, that is unique ...
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votes
2answers
395 views

Why do we need logical addressing [duplicate]

Possible Duplicate: Why couldn’t MAC addresses be used instead of IPv4|6 for networking? If physical address or Mac address is unique why do we need logical addressing? This because ...
3
votes
2answers
1k views

What is the Cisco iOS (CLI) command to display a WAP's Radio MAC address?

I can't believe I'm unable to find this with teh g00glez or by RTFMing, but does anyone know how to display the MAC address of a Cisco WAP's Radio (wifi connection) from the command line? show ...
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votes
2answers
751 views

Connectivity issues when setting guest MAC to the same as the host MAC on ESXi 5

I am using VMWare ESXi 5. The ESXi 5 host has a NIC with the MAC XXXX:XXXX:XXXX I have created a console port for that card. I have added a new guest named COMP and manually assigned the MAC address ...
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2answers
213 views

Find IP address from a MAC address

Is there anyway to find the IP address of a MAC address using a command? I was thinking something like arping might work but can't seem to find much information on it.
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1answer
2k views

Ping server NETBIOS name returns wrong IP and “Destination host unreachable”

Problem server is Windows 2008 R2 VM running on VMWare ESXi 4 host. Single network adapter manually assigned single IP address (192.168.1.11). When I ping the server from any other network computer, ...
155
votes
13answers
26k views

Why couldn't MAC addresses be used instead of IPv4|6 for networking? [closed]

I am reading up on TCP/IP and other related protocols and technologies. MAC addresses are described as being (reasonably :) unique, and as having a large possibility space (several hundred trillions), ...
0
votes
1answer
82 views

How to fix Parallels Management Node if DHCP server filters MAC address

I'm evaluating Parallels Server on Mac OS X  Lion Server, and during installation it sets up a "Management Node" VM for managing the other VMs. The problem is that my DHCP server is filtering MAC ...
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2answers
2k views

How do I find out which physical port my ethersvi MAC address corresponds to on a Cisco switch?

I'm doing a layer2 network map (my first) and this is the first virtual mac I've encountered. From the mac address table of switch1, I have VLAN 1 6416.8d98.52c0 DYNAMIC Te0/1 and on the ...
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votes
2answers
136 views

How does a device search for available wifi networks? [closed]

Say you have a wifi device (D) and a wifi router (R) that have never shared radio waves before, and are within range. How does D discover that R exists? Does R constantly broadcast a message with its ...
5
votes
2answers
2k views

Can I create a pf rule involving MAC address instead of IP?

The title is self explanatory. I want to create rules in pf running on OpenBSD 4.9 for perticular MAC address, something like pass in on eth0 from mac 00:04:34:5f:34:33 to mac 34:32:34:06:5e:22 I ...
1
vote
3answers
490 views

Get the MAC addresses of all the machines connected to a LAN when NO machines have got an IP address yet

Here is the real scenario. I have say 4 machines not having any IP address yet connected to a switch. In one of the machines (OS=CentOS), I would install a DHCP server and would provide the other ...
0
votes
2answers
1k views

Tie SSH key with MAC address

I have a ubuntu server which I scp files to often. It is setup for password-less authentication using a key I have on the server. Is it possible to tie a mac address to the key so that only my client ...
1
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2answers
3k views

ISP login, MAC spoofing, WiFi and multiple devices

I have a Tikona Digital Broadband (WiMax based) Internet Connection which allows limited number of devices to be connected at a time and also requires that the users login with username and password ...
1
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1answer
88 views

Is it possible to distinguish traffic from different computers from behind a router?

The mac address would be that of the router, I presume. But could I distinguish the ip addresses of the computers behind the router, or could I only see a global ip address that belongs to the router? ...
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1answer
2k views

Using Ipset and Iptables for MAC address filtering

I use MAC address filtering on my Linux router. Here is what I have done: iptables -A INPUT -i eth5 -m mac --mac-source 00:07:e9:84:2b:99 -j RETURN #User: Someuser iptables -A INPUT -i eth5 -j DROP ...
1
vote
2answers
575 views

How can I separate a VMWare Server from the host's MAC Address on my router?

I'm running a Debian LAMP Server in VMWare Player, using a bridged connection. However, on my router the VM is showing up with the same MAC Address... therefore I can't set the VM to a static ...
15
votes
3answers
2k views

Look up manufacturer based on Mac Address?

I want to incorporate into a piece of software the ability to look up a manufacturer based on a mac address. By googling "mac address lookup" and similar, I have noticed several websites that make ...
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vote
2answers
159 views

Cloning IP address and/or MAC address for server fail-over

I am currently providing some web applications to my customers (apache/php/mysql on Windows server). I'm looking to provide some sort of fail-over server in the case my server has a hardware failure. ...
0
votes
2answers
11k views

Query a Windows DHCP server : find MAC from hostname

From my computer, I want to query my DHCP server to find a specific mac adress. I want to enter the hostname to search, and getting back the Mac address. Something like : netsh dhcp server scope ...
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1answer
344 views

Assign arbitrary MAC address in VirtualBox VM

Is it possible to assign an arbitrary MAC address to an VirtualBox virtual machine instance? This answer suggests that it is only possible to generate MAC addresses where the most significant byte is ...
7
votes
2answers
5k views

NIC Teaming with Broadcom on HyperV 2008 R2

I have a HyperV cluster made up of 3 hosts. Each host is connected to both of my Nexus 5548 switches running in an etherchannel. LACP on the switch and NIC teaming using Broadcom 802.3ad on the server ...
6
votes
1answer
3k views

Is bonding mode=5 a solution against MAC flapping?

There is two are interconnected Cisco WS-2950T. By the one GBIC port on first switch connected a first NIC of bonding interface, and by the one GBIC port on second switch connected a second NIC of ...
3
votes
1answer
3k views

Ubuntu Linux - two interfaces, same subnet, different vlan - MAC/ARP issues

I'm attempting to setup a server that needs to have interfaces on the same IP subnet, but different VLANs: eth1.102 Link encap:Ethernet HWaddr 00:50:56:b1:00:0f inet addr:10.1.1.6 ...
1
vote
1answer
1k views

Managed Ethernet switch per-port MAC address translation?

Just a shot in the dark here, but I thought I'd ask in case anyone has some ideas: I've got a testing scenario where some (GUI-less/embedded) IPv6 devices are going to be temporarily plugged into the ...
4
votes
2answers
1k views

Using DHCP with Multi-Homed NICs

I am trying to steer away from our current manual addressing system and embrace the decades-old wonder of DHCP. In our domain and even at my home network DHCP is great - I can use address reservations ...