交换机配置讲义-2.ppt

Cisco Catalyst LAN SwitchSoftware Overview (2) Virtual LANs Creating Virtual LANs Set up VLANs for entire management domain from one Catalyst 6000 Up to 1000 active VLANs Two tasks: Creating VLANs in a management domain Grouping switch ports to VLANs Creating VLANs in a Management Domain Overview Use set vtp and set vlan commands to set up VLANs across management domain Default configuration has switches in a no-management domain state, all Ethernet ports in VLAN 1 VTP advertisement gives switch its management domain name and configuration revision number Understanding VLAN Types Five types of VLANs Ethernet FDDI Token Ring/802.5 FDDI-net Token Ring-net FDDI and Token Ring VLAN types represent single logical ring with one ring number FDDI-net and Token Ring-net VLAN Types In a source-routing environment, ring segment and extended LAN may be different: FDDI-net and Token Ring-net types represent set of ring segments connected by source-route bridges FDDI and Token Ring VLAN types have FDDI-net or Token Ring-net parent VLANs VLAN Routing Routers also need to be configured VLAN = subnet VLAN routing is fast-switched across all router platforms Cisco IOS software Release 11.1(2) supports VLAN routing between ISL interfaces and native interfaces for IP and IPX Implemented using subinterfaces VLAN Trunking Inter-Switch Link (ISL) Tagging Performed in hardware Effective between switches, routers, intelligent server NICs Not intrusive to client stations Protocol-independent ISL Frames Frames encapsulated with ISL header and CRC Support for: Catalyst 5000 supports 1000 VLANs (2.3) Cisco 7000 series support 255 VLANs Catalyst 3000 supports 64 VLANs Implemented in ASICs for wire speed performance ISL Frame Header VLAN 15-bit descriptor Only the lower 10 bits are used to provide 1024 VLANs BPDU 1-bit descriptor identifying spanning-tree BPDU and CDP frames If set, the frame is sent immediately to the NMP for processing VLAN Trunk Protocol Why Do We Need VTP? VTP info