We got a bunch of port-sec violations on port fa1/0/42. after checking logs, we noticed that the MAC address responsible for generating the alert was not one, but many. We asked the user, he said he only restarted his computer. The MAC addresses happen to be existing MAC on the network.

Some vendors write the MAC address with dots. So he is talking about MAC address. As mentioned in the answer, a device with multiple (LAN, WLAN) interfaces will have several MAC addresses, sometimes listed on the case, sometimes not. Sometimes they are +1 to the base address listed on the case. – flohack Nov 19 '15 at 16:48 An octet, in computer networking, is any number that can be represented by 8 bits. In this case, two hexadecimal digits can represent the same numbers that 8 bits can. Now, you may have noticed that we mentioned that MAC addresses are globally unique, which might have left you wondering how that could possibly be. An IP router has to have a minimum of 2 IP addresses, because its function is deciding on where to send the packet next. A minimal configuration of TCP/IP network where you need a router is a connection between two networks with different network part of the network addresses. Sep 03, 2013 · Since ethernet uses MAC addresses, the sender needs to get the MAC address of the next hop. There is a special protocol ARP (address resolution protocol) that is used for that. Once the sender has retrieved the MAC address of the next hop, he writes that target MAC address into the packet and sends the packet. Unlike IPv4 addresses which are 32-bits long, the Ethernet MAC address is 48-bits in length and can provide a total of 281.5 trillion possible addresses. The first 3 bytes (24-bits) are reserved for identifying the vendor or manufacturer while the remaining 3 bytes (24-bits) are used to provide unique addresses to each device. Jul 15, 2008 · Well, the WAN is the Internet side, and that's the side the modem (internal or external) connects to. The LAN and wireless don't have to have separate MAC addresses, as evidenced by mine that has the same one. Truthfully, I don't know why one MAC address wouldn't be sufficient. Here's another router, a D-Link DIR-615, also with two MAC addresses. Jul 15, 2008 · Why Does My Router Have Three Mac Addresses? - posted in Networking: I have the ubiquitous Linksys WRT54G router, and when I go into its configuration settings under "Status", I can choose either

A media access control address (MAC address) is a unique identifier assigned to a network interface controller (NIC) for use as a network address in communications within a network segment. This use is common in most IEEE 802 networking technologies, including Ethernet , Wi-Fi , and Bluetooth .

Media Access Control (MAC) Address – MAC Addresses are unique 48-bits hardware number of a computer, which is embedded into network card (known as Network Interface Card) during the time of manufacturing. MAC Address is also known as Physical Address of a network device. In IEEE 802 standard, Data Link Layer is divided into two sublayers – How many network or MAC address can a network interface have? (My guess: one) My question is from the fact that a computer or a router can have multiple IP or MAC addresses. Does that mean the computer or router . have multiple network interfaces, each of which has an address, or

Nov 28, 2016 · The problem exists only when the router does not have an Attached Devices page. In such case, the virtual MAC address needs to be manually retrieved. To retrieve the MAC address: The two real MAC addresses can be found on the label on the back (EX6200) or on the bottom (EX6100): (the image above shows the EX6200 MAC addresses labels printed on

Address emails in Mail on Mac. You can send a message to one or more people, or to a group email address, and show or hide their email addresses. If you have multiple email addresses, you can choose which address to send your messages from and even an address for receiving replies. Open Mail for me Given that IP addresses can't be permanently assigned to a device — after all, a particular address can belong to one computer today and another one tomorrow — MAC addresses allow communication between devices on a local network by making it possible to reliably distinguish one computer from another. Nov 28, 2016 · The problem exists only when the router does not have an Attached Devices page. In such case, the virtual MAC address needs to be manually retrieved. To retrieve the MAC address: The two real MAC addresses can be found on the label on the back (EX6200) or on the bottom (EX6100): (the image above shows the EX6200 MAC addresses labels printed on