Shulou(Shulou.com)06/02 Report--

Construction of DHCP Relay Service in GNS3+CentOS 7

Here we need to run three virtual machines on the computer at the same time. One CentOS 7 as server and two windows 10 as clients. Layer 3 router and layer 2 switch are built on GNS3 to realize DHCP function and automatic allocation of IP address.

Experimental Topology Diagram of Relay Service

Install the dhcp package

Open the terminal on the CentOS 7 virtual machine and install the dhcp package

Open the connection after building the topology diagram on GNS 3.

Enter sw1 configuration

Create 3 vlan, namely vlan10, vlan20 and vlan100

Enter port f1max 1, assign it to vlan10, and set vlan mode to access

Enter port f1max 2, assign it to vlan20, and set vlan mode to access

Enter port f1max 3, assign it to vlan100, and set vlan mode to access

Enter interface f1max 0, set the vlan mode to Trunk, and specify the encapsulation protocol as 802.1q

Turn off the routing function

Enter sw2 configuration

Enter interface f1max 0, set the vlan mode to Trunk, and specify the encapsulation protocol as 802.1q

Create 3 vlan, namely vlan10, vlan20 and vlan100

Enter vlan10, configure IP address, and subnet mask, and turn it on

Enter vlan20, configure IP address, and subnet mask, and turn it on

Enter vlan100, configure IP address, and subnet mask, and turn it on

After the above configuration is complete, go back to the virtual machine, set VMnet8 to host-only mode, and turn off the dhcp service function

Set all the NICs of the three virtual machines to custom mode, and assign VMnet1 to the first win10, VMnet2 to the second win10, and VMnet8 to the CentOS 7 virtual server.

Enter terminal mode on CentOS7 and give CentOS7 this static network address

Change the automatic acquisition to a static manual configuration and enter the IP address. Subnet mask, gateway

Restart the network service and view the network card information

Copy the dhcp configuration file from the original path to / etc/dhcp/dhcpd.confxia

Modify subnet, add 3 vlan segments, assigned IP address range, and gateway

Restart the dhcp service and view

Return to GNS3 to continue configuring sw2

Enter vlan10,vlan20 and vlan100 and specify the port address of the DHCP server

Above, we have completed the configuration of the DHCP relay server

Next, we switch to the client side and view our information.

Use ipconfig to view Nic information on the first win10

Use ipconfig to view the Nic information on the second win10

If your network card is not available, it is recommended that you use "ipconfig / release" to close it, and then use "ipconfig / renew" to get it again.

Below we set up a client to be assigned a fixed IP address

First, we use "ipconfig / all" on the second client to get the local physical address.

Back to the CentOS 7 server

Enter the DHCP configuration file and modify the information under host fantasia

Restart the DHCP service

Return to the client to check the IP address

The above is the configuration of our DHCP midrange service.

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