To configure multiple IP addresses on a core switch, assign each IP to a separate VLAN interface (SVI) or Layer 3 interface, enabling routing between subnets.

Step 1: Ensure Layer 3 Capability

Core switches must support Layer 3 functionality. By default, most switch ports operate at Layer 2. To assign IP addresses, you need to configure Switched Virtual Interfaces (SVIs) or convert physical interfaces to Layer 3 interfaces .

Step 2: Create VLANs

Each IP address typically corresponds to a separate subnet, so you need a VLAN for each subnet:

CodeCopySwitch> enableSwitch# configure terminalSwitch(config)# vlan 10Switch(config-vlan)# name SalesSwitch(config-vlan)# exitSwitch(config)# vlan 20Switch(config-vlan)# name MarketingSwitch(config-vlan)# exit

Assign physical ports to the VLANs as access ports or configure trunk ports for inter-switch connections .

Step 3: Configure IP Addresses on VLAN Interfaces

Once VLANs are created, assign IP addresses to each VLAN interface:

CodeCopySwitch(config)# interface vlan 10Switch(config-if)# ip address 192.168.10.1 255.255.255.0Switch(config-if)# no shutdownSwitch(config-if)# exitSwitch(config)# interface vlan 20Switch(config-if)# ip address 192.168.20.1 255.255.255.0Switch(config-if)# no shutdownSwitch(config-if)# exit

Each VLAN interface now acts as a gateway for its subnet .

Step 4: Enable Routing Between VLANs

If the switch supports IP routing, enable it to allow communication between VLANs:

CodeCopySwitch(config)# ip routing

This allows devices in different VLANs to communicate through the core switch.

Step 5: Configure DHCP (Optional)

If the switch will provide DHCP for multiple VLANs, create DHCP pools for each subnet:

CodeCopySwitch(config)# ip dhcp pool SalesSwitch(dhcp-config)# network 192.168.10.0 255.255.255.0Switch(dhcp-config)# default-router 192.168.10.1Switch(dhcp-config)# exitSwitch(config)# ip dhcp pool MarketingSwitch(dhcp-config)# network 192.168.20.0 255.255.255.0Switch(dhcp-config)# default-router 192.168.20.1Switch(dhcp-config)# exit

This ensures devices in each VLAN receive the correct IP configuration .

Step 6: Verify Configuration

Use the following commands to confirm IP assignments and VLAN status:

CodeCopySwitch# show vlan briefSwitch# show ip interface briefSwitch# ping 192.168.10.1Switch# ping 192.168.20.1

This verifies that each VLAN interface is up and reachable. By following these steps, you can configure multiple IP addresses on a core switch, enabling it to route traffic between multiple subnets and manage different network segments efficiently .