• Enable Layer 3 on an individual interfaceINTERFACE modeip address• Enable the interface.INTERFACE modeno shutdownExample of Error Due to Issuing a Layer 3 Command on a Layer 2 InterfaceIf an interface is in the incorrect layer mode for a given command, an error message is displayed (shownin bold). In the following example, the ip address command triggered an error message because theinterface is in Layer 2 mode and the ip address command is a Layer 3 command only.Dell(conf-if)#show config!interface TenGigabitEthernet 1/2/1no ip addressswitchportno shutdownDell(conf-if)#ip address 10.10.1.1 /24% Error: Port is in Layer 2 mode Te 1/2/1.Dell(conf-if)#To determine the configuration of an interface, use the show config command in INTERFACE mode orthe various show interface commands in EXEC mode.Configuring Layer 3 (Interface) ModeTo assign an IP address, use the following commands.• Enable the interface.INTERFACE modeno shutdown• Configure a primary IP address and mask on the interface.INTERFACE modeip address ip-address mask [secondary]The ip-address must be in dotted-decimal format (A.B.C.D) and the mask must be in slash format (/xx).Add the keyword secondary if the IP address is the interface’s backup IP address.Example of the show ip interface CommandYou can only configure one primary IP address per interface. You can configure up to 255 secondary IPaddresses on a single interface.To view all interfaces to see with an IP address assigned, use the show ip interfaces briefcommand in EXEC mode as shown in View Basic Interface Information.To view IP information on an interface in Layer 3 mode, use the show ip interface command inEXEC Privilege mode.Dell>show ip int vlan 58Vlan 58 is up, line protocol is up382 Interfaces
