Vswitch principle and VTP (I) Switching Principle www.2cto.com review Ethernet Knowledge Sharing: HUB, layer, all ports are in a conflict domain and coexist in a broadcast domain. Switch: swtich, MAC. Each port belongs to a conflict domain, which is in a broadcast domain. Bridge: Ethernet frames are forwarded on the second layer, and data is forwarded based on MAC information. switch: high-performance bridge. more interfaces, higher efficiency, and richer features. the MAC table www.2cto.com of the vswitch is empty. Automatic learning: Keep dynamic (default) for 300 seconds. manual setting: static (secure) CCNP learning sw # sh mac-address-table aging-time // view the retention time of the MAC table the learning receives a data frame, learn the relationship between the source MAC address and the interface. 1 mac a F0/1 mac B F0/2 1 MAC C F0/3 1 MAC D F0/24 1 MAC E F0/24 description: when a port corresponds to a MAC address, it may be connected to a host. If a port corresponds to multiple MAC addresses, the port must be uplink) A vswitch or HUB. Two important functions of the vswitch MAC table: 1. The vswitch uses the MAC table to implement targeted data forwarding and improve efficiency. 2. in actual network applications, it is convenient for management personnel to troubleshoot the data forwarding process of network cables unicast: Check the MAC table with entries: targeted Forwarding (but when the source MAC and target MAC are the same port, discard-MAC filter) www.2cto.com has no entries: Spread the broadcast to all other ports in this segment, which are the same as those in the HUB: flood all other ports in this section. Diffusion 1. view the MAC table S2950 # sh mac-add to find the MAC correspondence between the host and the interface. 2. check the arp cache table S2950 # sh arp to find the relationship between the MAC address and IP address of the host. 3. sh cdp neighbors CDP cisco Neighbor Discovery protocol vtp VLAN trunk protocol VTP (vlan trunking protocol) function: automatically keeps VLAN information consistent through learning 1. select an important switch as the server and define the domain name wq.com. divide the corresponding VLAN as needed, such as V2 V3 V 4 V10. 2. add other switches to the domain wq.com and set them to the client. Www.2cto.com note: the link between the two switches must be a Trunk cable. Because VLAN information (VTP announcement) is transmitted through the Trunk. VTP announcement: the VLAN information version number (revision number) of the domain name password is initially 0, and each modification increases by 1. If no changes occur, the version number is released once every 5 minutes. (A new Vlan is added, and the version number is also increased.) three modes are available: the Server can create, modify, and delete VLANs and send VTP notices. The client C lient cannot create, modify, or delete VLANs, learn VTP notifications, and forward them. Transparent does not learn VTP information, but forwards it. You can create, modify, and delete VLAN information independently, but only locally. Note: When a new switch (server or client) is added to the network, you must ensure that the configuration revision number is 0. If it is higher than the original server, the VLAN information of the new switch overwrites the original VLAN information.