7.4.1 Packet Tracer - Implement DHCPv4 Answers
Topology
7.4.1 Packet Tracer – Implement DHCPv4
Addressing Table
| Device | Interface | IPv4 Address | Subnet Mask | Default Gateway |
|---|---|---|---|---|
| R1 | G0/0 | 192.168.10.1 | 255.255.255.0 | N/A |
| S0/0/0 | 10.1.1.1 | 255.255.255.252 | ||
| R2 | G0/0 | 192.168.20.1 | 255.255.255.0 | N/A |
| G0/1 | DHCP Assigned | DHCP Assigned | ||
| S0/0/0 | 10.1.1.2 | 255.255.255.252 | ||
| S0/0/1 | 10.2.2.2 | 255.255.255.252 | ||
| R3 | G0/0 | 192.168.30.1 | 255.255.255.0 | N/A |
| S0/0/1 | 10.2.2.1 | 255.255.255.252 | ||
| PC1 | NIC | DHCP Assigned | DHCP Assigned | DHCP Assigned |
| PC2 | NIC | DHCP Assigned | DHCP Assigned | DHCP Assigned |
| DNS Server | NIC | 192.168.20.254 | 255.255.255.0 | 192.168.20.1 |
Objectives
- Part 1: Configure a Router as a DHCP Server
- Part 2: Configure DHCP Relay
- Part 3: Configure R2 as a DHCP Client
Scenario
As the network technician for your company, you are tasked with configuring a Cisco router as a DHCP server to provide dynamic allocation of addresses to clients on the network. You are also required to configure the edge router as a DHCP client so that it receives an IP address from the ISP network. Since the server is centralized, you will need to configure the two LAN routers to relay DHCP traffic between the LANs and the router that is serving as the DHCP server.
Instructions
Part 1: Configure a Router as a DHCP Server
Step 1: Configure the excluded IPv4 addresses.
Configure R2 to exclude the first 10 addresses from the R1 and R3 LANs. All other addresses should be available in the DHCP address pool.
R2(config)# ip dhcp excluded-address 192.168.10.1 192.168.10.10 R2(config)# ip dhcp excluded-address 192.168.30.1 192.168.30.10
Step 2: Create a DHCP pool on R2 for the R1 LAN.
a. Create a DHCP pool named R1-LAN. The pool name must match this value in order for you to get credit for your configuration.
R2(config)# ip dhcp pool R1-LAN
b. Configure the DHCP pool to include the network address, the default gateway, and the IP address of the DNS server.
R2(dhcp-config)# network 192.168.10.0 255.255.255.0 R2(dhcp-config)# default-router 192.168.10.1 R2(dhcp-config)# dns-server 192.168.20.254
Step 3: Create a DHCP pool on R2 for the R3 LAN.
a. Create a DHCP pool named R3-LAN (case-sensitive).
R2(config)# ip dhcp pool R3-LAN
b. Configure the DHCP pool to include the network address, the default gateway, and the IP address of the DNS server.
R2(dhcp-config)# network 192.168.30.0 255.255.255.0 R2(dhcp-config)# default-router 192.168.30.1 R2(dhcp-config)# dns-server 192.168.20.254
Part 2: Configure DHCP Relay
Step 1: Configure R1 and R3 as a DHCP relay agent.
R1:
R1(config)# interface gigabitethernet 0/0 R1(config-if)# ip helper-address 10.1.1.2
R3:
R3(config)# interface gigabitethernet 0/0 R3(config-if)# ip helper-address 10.2.2.2
Step 2: Set PC1 and PC2 to receive IP addressing information from DHCP.
Part 3: Configure R2 as a DHCP Client
Step 1: Configure the Gigabit Ethernet 0/1 interface on R2 to receive IP addressing from DHCP.
R2(config)# interface gigabitethernet 0/1 R2(config-if)# ip address dhcp
Step 2: Activate the interface.
R2(config-if)# no shutdown
Device Configs - Final
ROUTER R1
! ============================================================== !--- 7.4.1 Packet Tracer - Implement DHCPv4 !--- ANSWER SCRIPT FOR ROUTER R1 !--- Usage: copy this whole file and paste it into the R1 terminal (start at the R1> prompt). Every line beginning with "!" is a comment; IOS ignores it, so pasting a comment by accident is harmless. ! ============================================================== enable configure terminal ! -------------------------------------------------------------- !--- Part 2: Configure DHCP Relay. ! -------------------------------------------------------------- !--- Step 1. Helper address on the LAN interface: R2 S0/0/0 (10.1.1.2), so PC1 DHCP requests reach the R1-LAN pool on R2. interface gigabitethernet 0/0 ip helper-address 10.1.1.2 exit end ! -------------------------------------------------------------- !--- Save the configuration to NVRAM. (Press Enter when prompted for the destination filename.) ! -------------------------------------------------------------- copy running-config startup-config ! ============================================================== !--- Verification: !--- show running-config interface gigabitethernet 0/0 -> ip helper-address 10.1.1.2 !--- PC1 (DHCP) -> 192.168.10.11 or higher, gateway 192.168.10.1, DNS 192.168.20.254 ! ==============================================================
ROUTER R2
! ============================================================== !--- 7.4.1 Packet Tracer - Implement DHCPv4 !--- ANSWER SCRIPT FOR ROUTER R2 !--- Usage: copy this whole file and paste it into the R2 terminal (start at the R2> prompt). Every line beginning with "!" is a comment; IOS ignores it, so pasting a comment by accident is harmless. ! ============================================================== enable configure terminal ! -------------------------------------------------------------- !--- Part 1: Configure a Router as a DHCP Server. ! -------------------------------------------------------------- !--- Step 1. Exclude the first 10 addresses of the R1 and R3 LANs. ip dhcp excluded-address 192.168.10.1 192.168.10.10 ip dhcp excluded-address 192.168.30.1 192.168.30.10 !--- Step 2. DHCP pool R1-LAN (exact name): network, default gateway and DNS server. ip dhcp pool R1-LAN network 192.168.10.0 255.255.255.0 default-router 192.168.10.1 dns-server 192.168.20.254 exit !--- Step 3. DHCP pool R3-LAN (case-sensitive): network, default gateway and DNS server. ip dhcp pool R3-LAN network 192.168.30.0 255.255.255.0 default-router 192.168.30.1 dns-server 192.168.20.254 exit ! -------------------------------------------------------------- !--- Part 3: Configure R2 as a DHCP Client. ! -------------------------------------------------------------- !--- Step 1. G0/1 receives its IP addressing from the ISP by DHCP; Step 2. activate the interface. interface gigabitethernet 0/1 ip address dhcp no shutdown exit end ! -------------------------------------------------------------- !--- Save the configuration to NVRAM. (Press Enter when prompted for the destination filename.) ! -------------------------------------------------------------- copy running-config startup-config ! ============================================================== !--- Verification: !--- show ip interface brief -> GigabitEthernet0/1 has a 209.165.200.x address, Method DHCP, up/up (use Fast Forward Time) !--- show ip dhcp binding -> one lease in 192.168.10.0/24 (PC1) and one in 192.168.30.0/24 (PC2) ! ==============================================================
ROUTER R3
! ============================================================== !--- 7.4.1 Packet Tracer - Implement DHCPv4 !--- ANSWER SCRIPT FOR ROUTER R3 !--- Usage: copy this whole file and paste it into the R3 terminal (start at the R3> prompt). Every line beginning with "!" is a comment; IOS ignores it, so pasting a comment by accident is harmless. ! ============================================================== enable configure terminal ! -------------------------------------------------------------- !--- Part 2: Configure DHCP Relay. ! -------------------------------------------------------------- !--- Step 1. Helper address on the LAN interface: R2 S0/0/1 (10.2.2.2), so PC2 DHCP requests reach the R3-LAN pool on R2. interface gigabitethernet 0/0 ip helper-address 10.2.2.2 exit end ! -------------------------------------------------------------- !--- Save the configuration to NVRAM. (Press Enter when prompted for the destination filename.) ! -------------------------------------------------------------- copy running-config startup-config ! ============================================================== !--- Verification: !--- show running-config interface gigabitethernet 0/0 -> ip helper-address 10.2.2.2 !--- PC2 (DHCP) -> 192.168.30.11 or higher, gateway 192.168.30.1, DNS 192.168.20.254 ! ==============================================================
Download Packet Tracer (.pka) file:
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7.2.10 Packet Tracer – Configure DHCPv4
