ccna certification update

ccna certification update.IPv6 Routing Protocol is "application" Application Routing IPv6 Routing Protocol is "ND" Neighbor Discovery Routing IPv6 Routing Protocol is "rip cisco'* // RIPng RoutingInterfaces: GigabitEthernetO/1 Serial0/0/l//No other routes are redistributed to this process IPv6 Routing Protocolis "static" Static routesChapter 7 Switched NetworksA switch is the most important device in a LAN and is used to connect multiple devices in the same network. Switches work based on MAC addresses. This chapter introduces switching principles, forwarding methods, switching network hierarchy, switch management ( SSH), and switch security.7.1 Switching Network Overview7.1.1 Switch working principle From the traditional concept, the switch is a layer 2 (data link layer) device, based on the received data frame in the source MAC (Media AccessControl) address and the destination MAC address to work, with each port to enjoy a dedicated bandwidth, isolate the conflict domain, to achieve full-duplex operation and other advantages. Of course, the use of Layer 3 switches is now also very popular. The role of the switch is mainly two: one is to maintain the content address table (ContextAddressMemory, CAM) table, which is a mapping table of MAC addresses, switch ports and VLANs to which the ports belong; the second is to forward data frames according to the CAM table. For each data frame received, the switch compares the destination MAC address in the header of the data frame with the list of addresses in the MAC table, and if a match is found, the port number in the table that matches the MAC address is used as the forwarding out port for the frame. The switch uses the following five basic operations to perform switching functions.1 Learn: When the switch receives a data frame from an interface, the switch reads the source MAC address of the frame and fills the MAC table with the MAC address and its corresponding port.2Expire: The MAC table entry acquired through learning has a timestamp that is used to remove the old entry from the MAC table. Once an entry is created in the MAC table, it starts a decreasing count using its timestamp as the starting value. After the count value reaches 0, the entry is deleted, also known as aging. The switch will refresh that entry in the MAC table, that is, retime it, if it receives frames from the same port with the same source MAC address. The default aging time for a Cisco switch MAC table entry is 300 seconds.3 Flooding: If the destination MAC address is not in the MAC table and the switch does not know which port to send the frame to, it sends the frame to all other ports in the same VLAN except the receiving port, a process called unknown unicast frame flooding. Flooding is also used to send frames whose destination address is a broadcast or multicast MAC address.