Task 1: Configure IP addressing on G0/1 interface of R1 and R2.

On R1:

R1# configure terminal
R1(config)# interface g0/1
R1(config-if)# ip address 192.168.1.1 255.255.255.0
R1(config-if)# no shutdown
R1(config-if)# end

On R2:

R2# configure terminal
R2(config)# interface g0/1
R2(config-if)# ip address 192.168.2.1 255.255.255.0
R2(config-if)# no shutdown
R2(config-if)# end

Task 2: Configure R1 to act as a relay agent and forward DHCP requests to the DHCP server.

R1 must forward DHCP requests from its G0/1 interface (branch client subnet) to the centralized DHCP server. Since we do not know the IP address of the DHCP server, we can determine it by checking the IP address of R1's G0/0 interface. Given that the subnet mask of the network between R1 and the DHCP server is /30 (255.255.255.252), which allows only two usable IP addresses, the DHCP server's IP will be the other address in that subnet.

We can use the command show ip interface brief command for this.

R1# show ip interface brief

Interface              IP-Address      OK? Method  Status                Protocol

GigabitEthernet0/0     192.168.100.2   YES Manual  up                    up

GigabitEthernet0/1     192.168.1.1     YES Manual  up                    up

--- Output Omitted ---

Since IP address of R1's G0/0 interface is 192.168.100.2 then IP address of DHCP server's interface must be 192.168.100.1. We need to assign this as helper address on the G0/1 interface of R1.

R1# configure terminal
R1(config)# interface g0/1
R1(config-if)# ip helper-address 192.168.100.1

ip helper-address 192.168.100.1: Configures R1 to forward DHCP requests from clients on 192.168.1.0/24 to the DHCP server at 192.168.100.1

Task 3: Configure R2 to act as a relay agent and forward DHCP requests to the DHCP server.

We need to do the same thing on R2 to find the IP address of DHCP server's interface connected to R2.

R2# show ip interface brief
Interface              IP-Address      OK? Method  Status                Protocol
GigabitEthernet0/0     192.168.101.2   YES Manual  up                    up
GigabitEthernet0/1     192.168.2.1     YES Manual  up                    up
--- Output Omitted ---

Since IP address of R2's G0/0 interface is 192.168.101.2 then IP address of DHCP server's interface must be 192.168.101.1. We need to assign this as helper address on the G0/1 interface of R2.

R2# configure terminal
R2(config)# interface g0/1
R2(config-if)# ip helper-address 192.168.101.1

ip helper-address 192.168.101.1: Configures R1 to forward DHCP requests from clients on 192.168.2.0/24 to the DHCP server at 192.168.101.1

Task 4: Verify DHCP Clients receive IP Address from the centralized DHCP Server.

From the client devices, configure the clients to obtain an IP address dynamically, and verify they receive an IP from the DHCP server.

Client1:\> ipconfig /renew
IP Address.................: 192.168.1.2
Subnet Mask................: 255.255.255.0
Default Gateway............: 192.168.1.1
DNS Server.................: 8.8.8.8

This command is used on a PC to request a new IP address from a DHCP server. It forces the client to release its current IP address (if any) and renew it by communicating with the DHCP server. The new IP address and related network configuration details (subnet mask, default gateway, DNS server) are obtained and applied to the system.

Client2:\> ipconfig /renew
IP Address.................: 192.168.2.2
Subnet Mask................: 255.255.255.0
Default Gateway............: 192.168.2.1
DNS Server.................: 8.8.8.8

Now exit configuration mode and save the configuration on both routers.

R1(config-if)# end
R1# write memory

R2(config-if)# end
R2# write memory