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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Can ISC-DHCP bind to Option 82 rather than Mac Addresses?

We use option 82 information to limit leases presently in ISC-DHCP using a spawn with statement for our billing subclass. This keeps a single household/business from obtaining more leases than they ...
2
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1answer
25 views

Virtual interfaces with different MAC addresses

I try to figure out how to set up two logical network interfaces (at one physical interface) with separate MAC addresses on a Linux machine. My first attempt was to use macvlan which seemed to work ...
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1answer
45 views

calculate reserved ip address based on mac address

Is it possible to calculate ip address based on mac address for isc-dhcp server? For example: 'aa:aa:aa:aa:aa:x' => '10.10.10.x' I have following in dhcpd.conf: subnet 10.10.10.0 netmask ...
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1answer
56 views

Can't find IPMI mac address

The MAC address listed under ipmitool lan print seems to be incorrect, since there is no entry in the arp cache for the set ip address, 10.224.242.121: # arp 10.224.242.121 10.224.242.121 ...
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1answer
89 views

Why are eno1 and eno2 in this order?

I've just installed a Fedora 21 Workstation system, and it's reversed the order of eno1 and eno2 from the CentOS 6 system that was on here before. lspci | grep Eth 00:19.0 Ethernet controller: Intel ...
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2answers
437 views

Do cellular network adapters (3G/4G/LTE) have MAC addresses?

We are implementing SSH restrictions by restricting by MAC address in iptables. Without the MAC address restrictions, using an app like iSSH, it's easy to access my server on the go to check on it's ...
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1answer
32 views

The Router Mac Address [closed]

Some sites can get the mac address of my network interface bu using cookies or java script ! but can they get my router mac address ?
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1answer
104 views

How can I get a report of all MAC addresses nearby? [duplicate]

I am trying to get an idea of how to get a list of all the MAC/IP's near my network. I've tried arp -a commands (What I found from some previous searching.) but those are not showing any of the ...
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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 ...
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0answers
18 views

Polycom VOIP phone seems to mask the secondary device's MAC address from a Cisco switch

When I have a Polycom VOIP phone plugged into a Cisco switch and a laptop plugged into the Polycom phone I get the following. 1) The phone goes into the voice VLAN as expected. 2) The laptop goes ...
3
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4answers
14k views

Can I use nmap to discover IPs and mac addresses?

When I need to locate the IPs of devices by their mac address on a Windows system, I normally use Advanced IP Scanner (from radmin.com) to scan the network, then I use arp -a to list the mac ...
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2answers
45 views

Is there a way to query all the mac addresses in a network?

I know this question was flagged "off-topic" and "non-professional", but when creating a gateway or IDS, this might be quite relevant. Also, Google finds nothing usable... There is a thing called ...
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1answer
37 views

Allowing a device blocked by port-security

Lets say I have port security configured on a switch's ports like this: Secure Port MaxSecureAddr CurrentAddr SecurityViolation Security Action (Count) (Count) ...
3
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1answer
108 views

What does the MAC setting on an interface do to the ability to transmit frames?

I'm told that an interface can transmit a frame no matter what the OS has set for the interface's MAC. I'm also under the impression this is how VMs do host-bridging. If that is so, then what uses the ...
0
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1answer
30 views

MAC ID Binding to IP on Windows

Is there a way i can bind a certain IP to have traffic allowed if it has a certain MAC ID on windows routing and remote access or network policies? Basically Associated MAC ID to IP xxx.xxx.xxx.xxx ...
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5answers
3k views

Find the network card mac address in Windows

How can I find the network card mac address in Windows (7)?
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1answer
109 views

virtualization and MAC addresses

I'm having trouble with some VMware VM problems. Short story, how can I deploy a Windows server 2008 R2 server image to a lab environment with snapshots without MAC issues. Long story, I have a 2008 ...
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2answers
70 views

Cisco 2801 - ACL example to prevent certain users in same subnet from accessing certain devices [closed]

May be a simple answer, but does anyone have an example of an ACL that would prevent certain users (preferably based on MAC address, so that I can not have to deal with static DHCP addressing) from ...
0
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1answer
17 views

Bridge behavior when MAC address is not found

Lets say, a uni-cast packet is sent from one system to another system. The packet passes goes to the bridge. But the bridge does not have any information about the MAC address of the destination. What ...
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1answer
176 views

Devices with MAC's manufacturer section “00:FF:01”?

While monitoring my office's network, I have seen a huge amount of traffic coming from devices whose MAC address manufacturer part (the three most significant octets) is 00:FF:01 I can't see the ...
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0answers
39 views

Wireless Client missing from MAC table

I am currently having problems with Wireless Clients loosing network connectivity, though still displaying a connection to their Wireless Access Point. I have 4 Wireless APs, each a Cisco WAP321 ...
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5answers
4k views

How do I MAC filter with DHCP server

I want to Only allow certain MAC addresses to get a IP from my DHCP server, currently I use dnsmasq and I rather not change dhcp server but I'm open to other software aswell. However, I need to be ...
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2answers
50 views

Capture a packet at the MAC layer

I want to implement a security solution similar to MACsec that captures a packet in its entirety (including the MAC header) at an intermediate network node (e.g linux based switch), perform some ...
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13answers
23k views

How to discover the MAC address of machines in a network?

How do I discover the MAC address of machines in a network? I need to discover the machines that are available just with only BIOS installed (no operating system). And I need to find the MAC address ...
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0answers
54 views

Do some network administrators assign MAC addresses with an unassigned OUI?

I am in a situation where I have observed MAC addresses on a network that do not belong to any assigned OUI range, and this is causing some issues. I suspect the cause here is a heavy use of ...
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42 views

Network access sometimes lost, disabling port security temporary solves?

I have network based primarily on Edge-Core managed switched. Port security with max mac count = 1 is enabled, DHCP snoopping enabled. Some clients have troubles with accesing network, but when I ...
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5answers
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how to generate a random MAC address from the Linux command line

How do I generate a random MAC address from the Linux command line? I search for a solution that only requires standard tools commonly found on the Linux command line. The MAC address will be used ...
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1answer
77 views

Does the IP -> Ethernet multicast address mapping ambiguity matter for IGMP snooping switches?

There are 2^28 possible IP multicast addresses, but only 2^23 possible Ethernet (MAC) multicast addresses (http://technet.microsoft.com/en-us/library/cc957928.aspx), which is why e.g. 224.1.1.1 gets ...
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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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5answers
28k views

What range of MAC addresses can I safely use for my virtual machines?

I want to assign my virtual machines MAC addresses so that I can configure DHCP reservations for them so that they always get the same IP address regardless of which host hypervisor they are running ...
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1answer
4k views

Two Identical mac addresses on the same lan - Tracking one down?

So I've been playing around with nmap, and found a curious problem, two devices in the same subnet have the same mac address. I would like to track down the second mac, as the first one is the sonic ...
0
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1answer
112 views

Linux static dhcp ip for visitor access internet without requesting MAC address? [closed]

Currently, my company internet access for visitor are required to request MAC address from them if they want to access to internet. Can we do something like the Hotel wifi? they just access to the ...
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934 views

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 ...
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STP/RSTP: what switch should do with MAC table on a port after changing STP role of this port?

I have two switches and two active links between them. Spanning Tree Protocol is enabled on both devices, and port roles are assigned correctly: there are two Designated/Forwarding ports on RootSwitch ...
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2answers
178 views

How to get a report of all mac addresses on another subnet?

We have an MPLS consisting of two branches: Location1 and Location2. I am using the Softperfect netscan to report all ip addresses and mac addresses of devices on Location1 where my workstation is ...
0
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1answer
130 views

Can RADIUS offer protection against spoofed MAC addresses accessing resources protected with MAC Authentication

When running RADIUS via WPA2 Enterprise and 802.1x, clients wishing to access the network must provide valid credentials. However, this does not stop malicious clients forging valid clients MAC ...
0
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1answer
130 views

Why does IPTraf show multiple MAC addresses for my interfaces?

Hopefully a simple question with a simple answer. I thought each NIC had a single MAC address. However, as can be seen from the IPTraf output below, I have multiple MAC addresses for both my eth0 and ...
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3answers
7k views

Cisco IOS router MAC or IP address filtering

I'm trying to filter a specific device from my network. Either MAC or IP address filtering would do the trick, but I have trouble finding the exact Cisco IOS commands to use. My router is a Cisco 870 ...
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3answers
145 views

Finding NAS devices on the LAN

Thanks to some lax record keeping by our (ex! :-) network manager I'm tasked with finding what QNAP and Synology NAS devices exist in our company. We have several hundred offices scattered across the ...
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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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1answer
509 views

How can I set up a transparent proxy using squid and squidguard which has time-based acl based on MAC addresses?

I have a linux based server and I want to control access to internet based on MAC addresses of devices. How can I do that?
2
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2answers
864 views

ARP responds with single MAC address on Linux server with multiple interfaces on the same network

Linux server has 2 active network interfaces: IF:eth1 IP:192.168.1.1/24 MAC:11:11:11:11:11:11 (1GbE) IF:eth2 IP:192.168.1.2/24 MAC:22:22:22:22:22:22 (10GbE) The idea is that the ...
3
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1answer
679 views

nmap and arp-scan inconsistent IP-MAC results

I seem to get variable and inconsistent results for the IP/MAC addresses from a particular machine, using nmap or arp-scan. The machine has 3 interfaces, and this is what it shows: $ uname -a Linux ...
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1answer
80 views

Strategy for forcing cam table updates from custom hardware

I have a system that consists of a control PC, two layers of switches, and 50 custom devices. The PC continuously streams a total of 5.8MB/sec (6000 ethernet frames/sec) to the devices. I have ...
2
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3answers
575 views

Can I run a single DHCP Server for all branches of an MPLS?

We have a two-location MPLS. I am told by the ISP that I can have a single DHCP server to service both branches. But I don't understand this. Consider this: Location1 (Host branch with the DHCP ...
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2answers
71 views

Network Switch Terminology (MAC address table) [closed]

When a switch has the ability to learn what MAC addresses each of its ports serves, then uses that to determine which port to send ethernet packets out, what is that feature called? Also, does every ...
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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, ...
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2answers
88 views

Is recipient's MAC address necessary for TCP connections across the internet? [closed]

I want to estabilish TCP connection over the internet between 2 computers which are in different local networks (the local networks use wifi). I have looked for description of TCP protocol, ...
2
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1answer
516 views

Questions about bridging VLANs

If, across the same building, I have two physically separate networks to connect devices together via simple switches, my understanding is that I could save myself some hardware-complexity if I were ...
2
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1answer
3k views

How to use Calling-Station-Id on a per user basis in freeRADIUS?

I am trying to limit every user to a small set of Mac-IDs in RADIUS, by directly including the appropriate information in the users file. It would be acceptable even if every user was limited to one ...