Cisco WS-C2980G-A Software Guide - Page 208

Understanding How VLANs Work Chapter 10 Configuring VLANs Figure 10-1 VLANs as Logically Defined Networks Cisco router Catalyst 4000 Engineering VLAN Marketing VLAN Fast Ethernet Catalyst 4000 Catalyst 4000 Accounting VLAN Floor 3 Floor 2 43990 Floor 1 VLANs are often associated with IP subnetworks. For example, all the end stations in a particular IP subnet belong to the same VLAN. Traffic between VLANs must be routed. Port VLAN membership on the switch is assigned manually on a port-by-port basis. When you assign switch ports to VLANs using this method, it is known as port-based, or static, VLAN membership. The in-band (sc0) interface of a switch can be assigned to any VLAN, so that you can access another switch on the same VLAN directly without a router. Only one IP address at a time can be assigned to the in-band interface. If you change the IP address and assign the interface to a different VLAN, the previous IP address and VLAN assignment are overwritten. You can set the following parameters when you create a VLAN in the management domain: • VLAN number • VLAN name • VLAN type (Ethernet) • VLAN state (active or suspended) • Maximum transmission unit (MTU) for the VLAN • Security association identifier (SAID) • VLAN number to use when translating from one VLAN type to another Note When translating from one VLAN type to another, you must create a different VLAN number for each media type. 10-2 Catalyst 4500 Series, Catalyst 2948G, Catalyst 2980G Switches Software Configuration Guide-Release 8.1 78-15486-01