14 – DHCP Server Configuration in Cisco Packet Tracer

14 – DHCP Server Configuration in Cisco Packet Tracer#

This tutorial is the fourteenth in our Cisco Packet Tracer series and introduces the configuration of a DHCP (Dynamic Host Configuration Protocol) server. DHCP automates IP address assignment, simplifying host configuration in networks of all sizes.

We’ll build a basic network with one router, two switches, six PCs, and one DHCP server. The DHCP server will dynamically assign IP addresses to all PCs in the network.

Find the CISCO pkt files in the repo -

Readme Card

Part 1 – Network Topology Overview#

This network includes:

  • One router (R0)

  • Two switches (S0, S1)

  • Six PCs (PC0–PC5)

  • One server (Server0) acting as the DHCP server, connected to Switch 0

Figure

Part 2 – Device Placement and Cabling#

Step 2.1 – Add Devices to the Workspace#

From Network Devices and End Devices, place:

  • 1 Router (2911)

  • 2 Switches (2960)

  • 6 PCs (PC0–PC5)

  • 1 Server (Server0)

Label as follows:

  • Router: R0

  • Switches: S0, S1

  • Server: Server0 (DHCP)

  • PCs: PC0–PC5

Figure

Step 2.2 – Cabling#

Use Copper Straight-Through connections:

From

To

Port

PC0–PC2

S0

fa0/1–fa0/3

Server0

S0

fa0/23

PC3–PC5

S1

fa0/1–fa0/3

S0

R0

fa0/24 → gig0/0

S1

R0

fa0/24 → gig0/1

Part 3 – IP Addressing Plan#

We’ll configure two subnets, one per switch:

Subnet

Range

Subnet Mask

192.168.1.0

Switch S0 (VLAN1)

255.255.255.0

192.168.2.0

Switch S1 (VLAN2)

255.255.255.0

Router interfaces:

Device

Interface

IP Address

R0

gig0/0

192.168.1.1

R0

gig0/1

192.168.2.1

The DHCP server will provide addresses within:

  • 192.168.1.10–192.168.1.100 for VLAN 1 (Switch 0)

  • 192.168.2.10–192.168.2.100 for VLAN 2 (Switch 1)

Part 4 – Configuration#

Now we will configure the DHCP server and router interfaces to enable automatic IP address assignment. It’s important to ensure the DHCP server is reachable from both VLANs and therefore we will set it up first.

Step 4.1 – Configure the DHCP Server#

  1. Click on Server0

  2. Go to the Desktop tab → Select IP Configuration

  3. Set the following values:

    • IPv4 Address: 192.168.1.2

    • Subnet Mask: 255.255.255.0

    • Default Gateway: 192.168.1.1

    Figure

    This ensures the DHCP server has a fixed IP address on the correct subnet and can communicate with the router.

  4. Now go to the Services tab

  5. From the left menu, select DHCP

  6. Make sure Service is turned On at the top

Warning

Ensure to turn on the ServerPool service in the DHCP settings, but don’t change any of its default settings.

Configure the first pool (for Switch 0 / VLAN 1)-#

  • Pool Name: LAN1

  • Default Gateway: 192.168.1.1

  • DNS Server: 0.0.0.0

  • Start IP Address: 192.168.1.10

  • Subnet Mask: 255.255.255.0

  • Maximum Number of Users: 90

  • Click Add

Figure

Configure the second pool (for Switch 1 / VLAN 2)-#

  • Pool Name: LAN2

  • Default Gateway: 192.168.2.1

  • DNS Server: 0.0.0.0

  • Start IP Address: 192.168.2.10

  • Subnet Mask: 255.255.255.0

  • Maximum Number of Users: 90

  • Click Add

Figure

You should now see both pools listed in the table at the bottom, showing their assigned configurations.

Figure

Step 4.2 – Configure Router Interfaces#

Note

We will be configuring the DHCP server to have the IP address 192.168.1.2 and we will use the ip helper-address command to forward DHCP requests from VLAN 2 to the DHCP server.

enable
configure terminal
hostname R0

interface g0/0
ip address 192.168.1.1 255.255.255.0
no shutdown
exit

interface g0/1
ip address 192.168.2.1 255.255.255.0
ip helper-address 192.168.1.2
no shutdown
exit

ip dhcp relay information trust-all
exit
write memory

Figure

Part 5 – PC Configuration and Testing#

Your network is now set up with a DHCP server and router. The next step is to configure the PCs to use DHCP for automatic IP address assignment.

Figure

Step 5.1 – Set PCs to Use DHCP#

  1. Click on each PC (PC0–PC5)

  2. Go to Desktop > IP Configuration

  3. Select DHCP (not static)

Each PC should automatically receive an IP address, subnet mask, default gateway, and DNS server.

Figure

Figure

Step 5.2 – Verify Connectivity#

From PC0, ping PC3:

Note

Make sure to check the IP address of PC3 before pinging as it may vary based on the DHCP assignment.

ping 192.168.2.32

Figure

From PC5, ping the DHCP server:

ping 192.168.1.2

Figure

You can also run:

ipconfig /all

This displays the IP address, gateway, and DNS settings assigned by DHCP.

Figure

Summary#

In this tutorial, you:

  • Built a two-switch, single-router network

  • Connected a DHCP server to automatically manage IP addresses

  • Configured two IP subnets for different LAN segments

  • Verified automatic address assignment using DHCP

DHCP simplifies network management by removing the need to manually assign IP addresses to each device—especially valuable in larger or frequently changing networks.

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