Why would it matter if a host is responding to Host A, or another host is sending something else to Host A? But the switch currently has no information where computer B is located. But by definition, a dumb switch is never accessed that way by a user. What if C suddenly sends a frame to A? One more example, if your switch supports per vlan mac address table, so no need to change the mac as well, as each mac address table will work separately without having an impact on the other ones! No need to go into any more detail than that. May be following are very basic questions for you guys but really difficult to understand for me. The fact that some marketing departments got a little term happy doesn't change that.
The advantage of a switch is that it allows for hundreds of network computer connections. Then, management traffic is addressed to the switch itself. This is encapsulated by mentioned layers. You could be using , which is non-routable. Settings in Ethernet interface view or Layer 2 aggregate interface view effect on the current port only. Okay, I'm in a dorm. Is it that it remembers the mac address of the destination desired by computer A, and when C tries to get to A it also contains its own mac address and the switch sees it isn't the same destination as computer A wanted? This isn't accomplishing routing so much as reducing network congestion.
I tested with this version adventerprisek9 -15. Recently I have been thinking about the same and came upon this question. In this case, the hardware address is 0003. Every network interface of every device router, switch port, etc. Where do I locate it? If so how would you find out what they are? I recently found that packets are encapsulated within ethernet frames. If the outgoing port is found, the frame is forwarded rather than broadcast, so broadcasts are reduced. I have two computers currently attached to this Switch.
Feel welcome to ask further! Now since it doesn't know the port to which B is connected, so it broadcasts packet at all of its ports and waits for all hosts to reply. Another rule: You never use another device's address as the source when sending your own messages. For example, my 4500s do not, but my 3560s do so. Frennzy: Cisco modular switches are also managed switches. Only the former determining next-hop is usually called routing.
Switches are unlike hubs or repeaters. For instance: Switch 00-01-aa-00-00-00 could have its ports like this: Port 1 00-01-aa-00-00-01 Port 2 00-01-aa-00-00-02 Port 3 00-01-aa-00-00-03 Port 4 00-01-aa-00-00-04 Port 9 00-01-aa-00-00-09 Port 10 00-01-aa-00-00-0A Port 11 00-01-aa-00-00-0B Port 16 00-01-aa-00-00-10 Port 17 00-01-aa-00-00-11 Port 24 00-01-aa-00-00-18 etc. Celeritas Your assumption in your question is wrong. So, now this 4 port switch inside this internet router box has to determine where computer 1 is located. I actually think they made up the labels after they plugged everything straight it to switches without a punch down panel.
How to Configure Your Switch Mac Address Table? One part is the slot number and the second part 4 bits are for the port number when you have a fixed number of slot and type i will explain latter. Dear Moallina 15, Greetings, Actually, you are right, you can get the switch's mac address from these commands, in addition to the command: show spanning-tree which shows the same mac address that is shown by the other commands! It would encapsulate an Ethernet frame and send it off toward the switch. Do not confuse a traditional router with that of a consumer based internet router that has many ports on the back of the box. So the switch does not get confused. I think it was mentioned as a gotcha when doing a show mac address-table Feel free to point me to the episode that it was covered in.
E9 02 regardless the vlan has a higher value i. Now switch nows about computer A. So, why does your network devices need two addresses to connect to a network? Say the switch table is empty. The router just sends the packets that are destined for the internal network to the switching hardware, then the switch will forward the packets on the correct ports. Do you have a good switch configuration recommendation that you want to share? What other switch topics would you like to see covered in this column? Then finally the packet is forwarded to B. Switches work at layer 2. For … All 15 Replies hello silvercats.
Let's assume that all of the devices are powered on but have not sent any traffic. It is important to note, if you actually give a shit about networking, that all network devices have their place. This process is called learning. Check out the , and catch up on David Davis' most recent columns. Based on such metrics it may be possible for sophisticated network analysis tools to say how many switches are on your network and maybe even make some guesses about the chips used in those switches.
Encapsulation means that a header with fields is added at each layer. A hub simply rebroadcasts every signal on every port to every other port, which while inefficient and slow is easy to create. The router has no knowledge where the computer is plugged into. If the addresses match, the packet is processed, otherwise it is discarded. Session management is the responsibility of higher layers.
We discovered a wing of our building's ethernet drops had been mislabeled by a contractor after a renovation project. Then to which interface packet is sent out? If computer A sends a frame destined to computer B, the switch will broadcast asking who has the mac address of B. Now the router wants to send a packet to 192. A switch, on the other hand, intelligently directs traffic between systems by routing packets only to their proper destination. We all know every switch port have already mac address associated with their port. Below is an example of a switch output table. The primary function of a switch is to forward frames based on their destination address so that in ideal case, they are forwarded only out the port that truly leads to the intended destination, and only if the destination is unknown or is a group of receivers multicasts, broadcasts , the frame is replicated out all ports except the one that the frame came in through.