CISCO CLI Create VLAN, Create DHCP, Create Gateway, Create Encapsulation, Create Trunk and Create Access Part 2

 Configuring Cisco devices involves separate steps on the
switch for VLANs and port modes, and on the router for inter-VLAN routing (encapsulation) and DHCP services. 
Switch Configuration (VLANs, Access, Trunk) 
These commands are executed on the Cisco switch to create VLANs and configure the ports. 

    Enter global configuration mode:
    cisco

    enable
    configure terminal

    Create VLANs:
    cisco

    vlan 10
    name DATA_VLAN
    vlan 20
    name VOICE_VLAN
    exit

    Configure Access Ports (for end devices like PCs/phones):
    cisco

    interface FastEthernet0/1  (or specific interface name)
    switchport mode access
    switchport access vlan 10
    exit

    Configure Trunk Ports (for links to other switches or routers):
    cisco

    interface GigabitEthernet0/1 (or specific interface name)
    switchport mode trunk
    switchport trunk encapsulation dot1q (Needed on some older or multi-layer switches)
    switchport trunk allowed vlan 10,20 (Optional: limits which VLANs are allowed)
    exit

     

Router Configuration (Encapsulation, Gateway, DHCP)
These commands are executed on the router to enable inter-VLAN routing and provide DHCP services. 

    Enter global configuration mode:
    cisco

    enable
    configure terminal

    Configure Encapsulation and Gateway (Router-on-a-stick):
    Create subinterfaces on the router's physical interface (e.g., GigabitEthernet0/0) for each VLAN. Each subinterface will serve as the default gateway for its respective VLAN.
        For VLAN 10:
        cisco

        interface GigabitEthernet0/0.10
        encapsulation dot1Q 10
        ip address 192.168.10.1 255.255.255.0 (This is the **default gateway** for VLAN 10 clients)
        no shutdown
        exit

        For VLAN 20:
        cisco

        interface GigabitEthernet0/0.20
        encapsulation dot1Q 20
        ip address 192.168.20.1 255.255.255.0 (This is the **default gateway** for VLAN 20 clients)
        no shutdown
        exit

    Configure DHCP Server:
    Create a separate DHCP pool for each VLAN's subnet, specifying the default router and DNS server.
        Exclude addresses (optional, but recommended for static IPs like the gateway):
        cisco

        ip dhcp excluded-address 192.168.10.1 192.168.10.5
        ip dhcp excluded-address 192.168.20.1 192.168.20.5

        Create pool for VLAN 10:
        cisco

        ip dhcp pool VLAN10_POOL
        network 192.168.10.0 255.255.255.0
        default-router 192.168.10.1
        dns-server 8.8.8.8 4.4.4.4 (Example public DNS servers)
        exit

        Create pool for VLAN 20:
        cisco

        ip dhcp pool VLAN20_POOL
        network 192.168.20.0 255.255.255.0
        default-router 192.168.20.1
        dns-server 8.8.8.8 4.4.4.4
        exit

    Save the configuration on both devices:
    cisco

    copy running-config startup-config