chapter 6 ccna 2

chapter 6 ccna 2.To configure a single-arm router, you need to divide the router's physical interfaces into multiple logical interfaces-subinterfaces. Cisco routers support up to 1000 interfaces, and this includes both physical and logical interfaces. After creating a sub-interface, the router will treat this logical interface as a physical interface: it can be assigned a Layer 3 address, disabled, and so on.To create a sub-interface, use the following command.Router(config)# interface type port_#.subinterface_# [point I multipoint]Router(config-subif)#After entering the physical interface type and port identifier, enter a period (.) and the subinterface number. The subinterface number takes on a value range of 0.4294967295. the only purpose of the subinterface number is to represent the subinterface in the IOS. the only requirement when creating a subinterface is that the subinterface number used be unique. Many administrators prefer to use the number of the VLAN to which the sub-interface belongs as the sub-interface number, but it is not necessary to do so because there is no relationship between the two numbers.If the interface is a serial interface, the connection type must be specified at the end of the command; otherwise, it can be omitted. The parameter point indicates a point-to-point connection, while multipoint indicates a point-to-multipoint connection (one interface connected to multiple devices). The parameter multipoint is used for interfaces that are connected (physically or logically) to multiple devices. When configuring a single-arm router, the connection type can be omitted because the connection type for LAN interfaces defaults to multipointo15.5.2 Encapsulation type of the interfaceAfter creating a subinterface, notice that the CLI prompt changes because it is now in subinterface configuration mode. If you want to route traffic between VLANs, you will need an interface that supports trunking. Some aspects are configured on the primary interface, while others are configured on the subinterface. Configurations such as duplex mode and speed are done on the primary (physical) interface, while most other configurations are done on the sub-interface (logical interface), which includes the VLAN to which the sub-interface belongs and the IP addressing information.Video 15.09.A multimedia demonstration of configuring a single-armed router is included in the digital resources that accompany this book. When configuring a subinterface for a single-armed router, you must configure the trunk type (ISL or 802.1Q) and the VLAN to which the subinterface belongs, as follows.