- #Multi switch mac address learning how to#
- #Multi switch mac address learning update#
- #Multi switch mac address learning Pc#
It does this by looking at the traffic that arrives from computers to read the source MAC address of the traffic. It then learns about where the different MAC addresses of those devices are connected.
What a switch does is that it constantly monitors the traffic which is entering the switch from connected devices. Whereas a hub just copies electrical signals between ports, a switch works intelligently with MAC addresses which have been mentioned previously to make sure that traffic that is sent between devices end up at the right place. The LAN ports of your home router where you can connect your internal computers, printers etcetera are in fact built-in switch ports that act exactly like the ports in a standalone switch.
#Multi switch mac address learning Pc#
Thus switch learns PC MAC address even before the data traffic flow or PING process.In fact, most people already have a switch at home, often without even knowing it. The destination IP address must be a PC2 IP address but here it has PC1 IP address, so it will drop the packet. At layer 3, it will check the destination IP address. Since it’s broadcast MAC address, it will accept and send to Layer 3. PC2 also receives the packet, and it will check the destination MAC address first. MAC Address Table Switch#show mac-address-table Now, if you run the command in Switch, you will see PC1 MAC-address entry in MAC address table.
#Multi switch mac address learning update#
The switch receives the packet, and it will learn the MAC address of the PC1, and it will update in the MAC address table. Since it’s a broadcast frame, it will be flooded to the network. It immediately generates an ARP packet with broadcast destination mac address and destination IP address with its own IP address 192.168.0.1.Īlso note that, in this packet, you can see the PC1 source MAC address and source IP address. MAC Address table Switch#show mac-address-table So there is no chance of learning PC MAC address by a switch.Īt this point, when we run the command in switch, then you will see no entry in the MAC address table.
So it will drop the frames and never send back a reply switch. Īs you know, PC is a layer 3 device, and it has no service to accept Layer 2 protocol frames. These frames have a multi-cast destination MAC address, so these frames will be flooded to both PCs. Usually, the switch sends Layer 2 protocol frames like STP(Spanning-tree protocol), CDP(Cisco Discovery Protocol), and DTP(Dynamic Trunking Protocol)in periodic time intervals. Both PCs have MAC addresses and the switch maintains the MAC address table, and it will learn all MAC addresses in the network. There is a switch in the middle and 2 PCs are connected to switch Ethernet ports. Note: There are not assigned IP Addresses to PCs. Let’s take an example of 2 PC’S connected to Switch.
#Multi switch mac address learning how to#