{"id":980,"date":"2013-11-12T10:20:50","date_gmt":"2013-11-12T16:20:50","guid":{"rendered":"http:\/\/www.poweradmin.com\/blog\/?p=980"},"modified":"2015-04-27T08:27:42","modified_gmt":"2015-04-27T13:27:42","slug":"how-to-implement-dhcp-relay-agent-roas-ospf-open-shortest-path-first","status":"publish","type":"post","link":"https:\/\/www.poweradmin.com\/blog\/how-to-implement-dhcp-relay-agent-roas-ospf-open-shortest-path-first\/","title":{"rendered":"How to implement DHCP"},"content":{"rendered":"

\n\tIn this article I am going to show how you can implement DHCP relay agent and inter-VLAN routing with OSPF (as shown in Figure. 1). Let\u2019s start with a short description of the scenario and then we will proceed through the step by step configuration guide.<\/span><\/span>\n<\/p>\n

\n\t\"DHCP<\/a>\n<\/p>\n

\n\tFigure. 1<\/strong><\/span><\/span>\n<\/p>\n

\n\t\u00a0\n<\/p>\n

\n\tScenario:<\/strong><\/span><\/span>\n<\/p>\n

    \n
  1. \n\t\tA DHCP server in the entire network must assign all the IP addresses that are required.<\/span><\/span>\n\t<\/li>\n
  2. \n\t\tWe have 5 different VLANs and Subnets named Accounting, Engineering, and Server on SW1 and Logistics & HSE on SW2. Devices that are in these VLANs need to be assigned the IP address automatically by a DHCP server.<\/span><\/span>\n\t<\/li>\n
  3. \n\t\tWe need inter-VLAN routing for all VLANs.<\/span><\/span>\n\t<\/li>\n
  4. \n\t\tTwo routers are connecting segment A to B (refer to Figure 1 above) and the ROAS is implemented on both of them.<\/span><\/span>\n\t<\/li>\n
  5. \n\t\tUse OSPF routing protocol to route packets between segment A and B.<\/span><\/span>\n\t<\/li>\n<\/ol>\n

    \n\t\u00a0\n<\/p>\n

    \n\tProcedure:<\/strong><\/span><\/span>\n<\/p>\n

    \n\tFirst let\u2019s create VLANs on SW1 and SW2. Login to the switch and issue the commands below in order to configure VLANs on the switches.<\/span><\/span>\n<\/p>\n

    \n\tSW1 Configuration:<\/em><\/span><\/span>\n<\/p>\n

    \n\tCreate VLANs according to the scenario and assign the ports to the VLANs:<\/span><\/span>\n<\/p>\n

    \n\tSwitch#config t<\/span><\/span>\n<\/p>\n

    \n\tSwitch(config)#hostname SW1<\/span><\/span>\n<\/p>\n

    \n\tSW1(config)#vlan 10<\/span><\/span>\n<\/p>\n

    \n\tSW1(config-vlan)#name Accounting<\/span><\/span>\n<\/p>\n

    \n\tSW1(config-vlan)#vlan 20<\/span><\/span>\n<\/p>\n

    \n\tSW1(config-vlan)#name Engineering<\/span><\/span>\n<\/p>\n

    \n\tSW1(config-vlan)#vlan 100<\/span><\/span>\n<\/p>\n

    \n\tSW1(config-vlan)#name Server<\/span><\/span>\n<\/p>\n

    \n\t\u00a0\n<\/p>\n

    \n\tAfter creating VLANs switchports to the vlans, you need to change the ports to access mode.<\/span><\/span>\n<\/p>\n

    \n\tSW1(config)#interface fastEthernet 0\/1<\/span><\/span>\n<\/p>\n

    \n\tSW1(config-if)#switchport mode access<\/span><\/span>\n<\/p>\n

    \n\tSW1(config-if)#switchport access vlan 10<\/span><\/span>\n<\/p>\n

    \n\tSW1(config)#interface fastEthernet 0\/2<\/span><\/span>\n<\/p>\n

    \n\tSW1(config-if)#switchport mode access<\/span><\/span>\n<\/p>\n

    \n\tSW1(config-if)#switchport access vlan 20<\/span><\/span>\n<\/p>\n

    \n\tSW1(config)#interface fastEthernet 0\/3<\/span><\/span>\n<\/p>\n

    \n\tSW1(config-if)#switchport mode access<\/span><\/span>\n<\/p>\n

    \n\tSW1(config-if)#switchport access vlan 100<\/span><\/span>\n<\/p>\n

    \n\tSW1(config)#interface fastEthernet 0\/23<\/span><\/span>\n<\/p>\n

    \n\tSW1(config-if)#switchport mode access<\/span><\/span>\n<\/p>\n

    \n\tSW1(config-if)#switchport access vlan 100<\/span><\/span>\n<\/p>\n

    \n\tVerify the settings by issuing the Show vlan brief<\/strong> command. The output should look similar to Figure. 2.<\/strong><\/span><\/span>\n<\/p>\n

    \n\t\"Show<\/a>\n<\/p>\n

    \n\tFigure. 2<\/strong><\/span> <\/span>\n<\/p>\n

    \n\t\u00a0\n<\/p>\n

    \n\tAccording to the scenario we need to implement Inter-vlan routing on the SW1. So we must designate a port as Trunk port<\/strong> to enable Inter-vlan routing on it and then we must connect this port to R1.<\/span><\/span>\n<\/p>\n

    \n\tTo make a port trunk port issue these commands in SW1 command line interface.<\/span><\/span>\n<\/p>\n

    \n\tSW1#config t<\/span><\/span>\n<\/p>\n

    \n\tSW1(config)#interface fastEthernet 0\/24<\/span><\/span>\n<\/p>\n

    \n\tSW1(config-if)#switchport trunk allowed vlan 10,20,100<\/span><\/span>\n<\/p>\n

    \n\tSW1(config-if)#switchport mode trunk<\/span><\/span>\n<\/p>\n

    \n\tNow let\u2019s add the first router to the packet tracer and configure ROAS for Inter-vlan routing. To configure Inter-vlan we must make 4 virtual interfaces on one of the R1\u2019s Fast-Ethernet interfaces. Here I am going to use Fa0\/0 to add these virtual interfaces.<\/span><\/span>\n<\/p>\n

    \n\tRouter>en<\/span><\/span>\n<\/p>\n

    \n\tR1#config t<\/span><\/span>\n<\/p>\n

    \n\tR1(config)#hostname R1<\/span><\/span>\n<\/p>\n

    \n\tR1(config)#interface fastEthernet 0\/0<\/span><\/span>\n<\/p>\n

    \n\tR1(config-if)#no shutdown<\/span><\/span>\n<\/p>\n

    \n\tR1(config-if)#exit<\/span><\/span>\n<\/p>\n

    \n\tR1(config)#interface fastEthernet 0\/0.10<\/span><\/span>\n<\/p>\n

    \n\tR1(config-subif)#encapsulation dot1Q<\/span><\/span>\n<\/p>\n

    \n\tR1(config-subif)#ip address 192.168.10.254 255.255.255.0<\/span><\/span>\n<\/p>\n

    \n\tR1(config-subif)#exit<\/span><\/span>\n<\/p>\n

    \n\tR1(config)#interface fastEthernet 0\/0.20<\/span><\/span>\n<\/p>\n

    \n\tR1(config-subif)#encapsulation dot1Q<\/span><\/span>\n<\/p>\n

    \n\tR1(config-subif)#ip address 192.168.20.254 255.255.255.0<\/span><\/span>\n<\/p>\n

    \n\tR1(config-subif)#exit<\/span><\/span>\n<\/p>\n

    \n\tR1(config)#interface fastEthernet 0\/0.100<\/span><\/span>\n<\/p>\n

    \n\tR1(config-subif)#encapsulation dot1Q<\/span><\/span>\n<\/p>\n

    \n\tR1(config-subif)#ip address 192.168.100.254 255.255.255.0<\/span><\/span>\n<\/p>\n

    \n\tR1(config-subif)#exit<\/span><\/span>\n<\/p>\n

    \n\t\u00a0\n<\/p>\n

    \n\tInter-vlan routing is now functional. It is time to add a DHCP server and configure the server to lease IPs to the clients in segment A.<\/span><\/span>\n<\/p>\n

    \n\tClick on the server and assign the IP address of the server on Desktop tab as depicted in Figure. 3.<\/strong><\/span><\/span>\n<\/p>\n

    \n\t\"DHCP<\/a>\n<\/p>\n

    \n\tFigure. 3<\/strong><\/span><\/span>\n<\/p>\n

    \n\t\u00a0\n<\/p>\n

    \n\tTo configure the DHCP server click on the Config tab and assign the Scopes parameters as shown in Figure. 4<\/strong>.<\/span><\/span>\n<\/p>\n

    \n\t\"Configure<\/a>\n<\/p>\n

    \n\tFigure. 4<\/strong><\/span><\/span>\n<\/p>\n

    \n\t\u00a0\n<\/p>\n

    \n\tTo test if the configuration is working or not click on the PC4 and set the IP configuration settings to DHCP. In Figure.5<\/strong> you can see that PC4 has obtained its IP lease from the server.<\/span><\/span>\n<\/p>\n

    \n\t\"Test<\/a>\n<\/p>\n

    \n\tFigure. 5<\/strong><\/span><\/span>\n<\/p>\n

    \n\t\u00a0\n<\/p>\n

    \n\tTo read the rest of the Article, go to <\/span>How To Implement DHCP \u2013 Part 2<\/span><\/a><\/strong><\/span><\/span>\n<\/p>\n

    \n\t\u00a0\n<\/p>\n

    \n\t\u00a0\n<\/p>\n

    \n\t\u00a0\n<\/p>\n

    \n\t\u00a0<\/p>\n","protected":false},"excerpt":{"rendered":"

    In this article I am going to show how you can implement DHCP relay agent and inter-VLAN routing with OSPF (as shown in Figure. 1). Let\u2019s start with a short description of the scenario and then we will proceed through the step by step configuration guide. Figure. 1 \u00a0 Scenario: A DHCP server in the […]<\/p>\n","protected":false},"author":5,"featured_media":989,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5,9,8],"tags":[],"class_list":["post-980","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-how-to","category-technical","category-windows"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t