Lab 033 How to configure OSPFv2 Point-to-point

CCNA 200-301 Chapter 3 IP Connectivity Lab 033 Configure and Verify OSPFv2 Point-to-point

Watch Full Demo on YouTube:

Lab Objective:

Open Shortest Path First version 2 (OSPFv2) is a widely used link-state routing protocol for IPv4 networks.

OSPFv2 is designed to establish neighbor adjacencies and share routing information within a single or multiple areas.

OSPF is well-suited for larger enterprise networks due to its scalability and efficiency in calculating the shortest path.

In this lab, we will focus on configuring and verifying OSPFv2 on point-to-point links between routers.

OSPF operates differently on point-to-point networks compared to broadcast networks, which simplifies adjacency establishment and avoids Designated Router (DR) and Backup Designated Router (BDR) elections.

This lab will walk through the configuration and verification of OSPFv2 on point-to-point connections using Cisco routers.

Lab Topology:

CCNA 200-301 Lab Chapter 3 IP Connectivity Lab 033 Configure & Verify OSPFv2 Point-to-point – Topology

Equipment Required:

3x Cisco Router (e.g., Cisco ISR4331/K9)
2 x Cisco Switches (e.g., WS-C2960-24TT-L)
4 x Laptops with Ethernet Interface Card
Console Cable
Ethernet Cable for connections between devices
Computer with Terminal emulation software e.g. PuTTY

IPv4 Address Table:

A. IPv4 Address Table:

Device Name	Interface ID	IP Address	Subnet-Mask
R1	Loopback0	1.1.1.1	255.255.255.255
R1	Se0/3/1	10.1.3.1	255.255.255.252
R1	Gig0/1	192.168.10.254	255.255.255.0

R2	Loopback0	2.2.2.2	255.255.255.255
R2	Se0/3/0	10.2.3.1	255.255.255.252
R2	Gig0/1	192.168.20.254	255.255.255.0

R3	Loopback0	3.3.3.3	255.255.255.255
R3	Se0/3/1	10.1.3.2	255.255.255.252
R3	Se0/3/0	10.2.3.2	255.255.255.252

B. Hosts IP Address Table:

Device Name	Interface ID	IPv4 Address/Subnet-Mask	Default Gateway
PC1	Fa0	192.168.10.1/24	192.168.10.254
PC2	Fa0	192.168.10.2/24	192.168.10.254
PC3	Fa0	192.168.20.3/24	192.168.20.254
PC4	Fa0	192.168.20.4/24	192.168.20.254

List of Command Summary:

Command	Command Description
enable	enters privileged EXEC mode.
configure terminal	enters global configuration mode from privileged EXEC mode.
hostname [hostname]	assign a device name to router.
show interfaces status	provides a summary of the current status of all interfaces on a Cisco switch. This command displays important information about each interface, including: Port: The interface identifier (e.g., Gi1/0/1). Name: The name or description assigned to the interface, if any. Status: The operational status of the interface (e.g., connected, notconnect, err-disabled). Vlan: The VLAN that the interface is assigned to. Duplex: The duplex mode of the interface (e.g., full, half, auto). Speed: The speed of the interface (e.g., 10, 100, 1000 Mbps, auto). Type: The type of interface (e.g., 10/100/1000BaseTX, SFP). This command is useful for quickly assessing the operational state and configuration details of all interfaces on the switch.
show ip ospf database	used to display the OSPF link-state database (LSDB) for the router. The LSDB contains information about all OSPF routers and their links within a particular area
show ip ospf neighbor	used to display the state of OSPF neighbors, which are other OSPF routers that the local router is directly connected to and has formed an adjacency with
show ip ospf	used to display general OSPF information, such as the OSPF process ID, router ID, area configuration, and OSPF timers
show ip ospf neighbor	used to display information about OSPF neighbor relationships. It provides details about the routers with which an OSPF router has established an adjacency. This command is useful for troubleshooting OSPF neighbor issues and verifying that OSPF adjacencies are forming correctly
show ip ospf neighbor detail	provides more in-depth information about the OSPF neighbors than the basic show ip ospf neighbor command. It displays detailed information on OSPF neighbors and the state of OSPF adjacencies. This command is particularly useful for troubleshooting OSPF neighbor issues and gaining deeper insights into OSPF behavior on a per-neighbor basis.
show ip route	is used on Cisco routers and Layer 3 switches to display the current IP routing table. Here’s what this command provides and its significance: 1. Routing Table: The main purpose of show ip route is to show the IP routing table maintained by the device. This table contains information about networks and subnets that the device knows about and how to reach them. It includes entries for directly connected networks, routes learned dynamically through routing protocols (such as OSPF or EIGRP), and static routes configured manually. 2. Routing Information: Each entry in the routing table typically includes: a. Destination network or subnet (e.g., 192.168.1.0/24) b. Next-hop IP address or exit interface to reach the destination c. Administrative distance (a metric used to determine the reliability of the route) d. Route type (e.g., connected, static, or learned via a routing protocol) e. Metric or cost associated with the route 3. Routing Decisions: The show ip route command helps network administrators troubleshoot connectivity issues and verify the routing paths configured on the device. By examining the routing table, administrators can determine how traffic will be forwarded based on destination IP addresses and make adjustments as needed. 4. Dynamic Updates: If routing protocols are enabled on the device, such as OSPF (Open Shortest Path First) or EIGRP (Enhanced Interior Gateway Routing Protocol), show ip route will display routes learned dynamically from neighboring routers participating in the same routing domain.
description “DESCRIPTION OF SOME SORT”	used to assign a descriptive text label to a network interface on a device such as a router or switch. This description helps administrators to identify the purpose or details of the interface more easily when managing and troubleshooting the network.
show ip interface brief \| include lan	used on Cisco devices to display a summarized list of all IP interfaces configured on the device and filter the output to only show interfaces that contain the keyword “lan” in their configuration. This command is helpful for quickly identifying and troubleshooting interfaces related to LAN (Local Area Network) configurations within the device’s network environment
ipconfig /all	used in Windows operating systems to display detailed information about all network interfaces and their configurations.
no shutdown	enables an interface.
show running-config	save the running configuration to the startup-configuration file.
show running-config \| section interface GigabitEthernet0/*	used to display the configuration details of a specific GigabitEthernet interface (interface GigabitEthernet0/) within the running configuration of a Cisco device. This command allows you to view the configuration settings related to the specified interface only, filtering out other configuration sections. It provides a focused view of the configuration parameters associated with the specified interface, including its IP address, VLAN membership, trunking settings, and any other relevant configuration details. The asterisk (*) is a wildcard character that matches any character or sequence of characters. In this context, it is used to match any subinterface under GigabitEthernet0.
show running-config \| section interface FastEthernet0/1$	The “show running-config \| section interface FastEthernet0/1$” command is similar to the previous one, but it focuses specifically on the FastEthernet0/1 interface. The “$” symbol at the end of the interface name indicates that the command will match only the interface that ends with “FastEthernet0/1”. This command is helpful when you want to view the configuration details of a specific FastEthernet interface without displaying configurations for other interfaces.
copy running-config startup-config	used to save the currently running configuration (stored in the RAM) to the startup configuration (stored in the NVRAM)
router ospf [OSPF ID]	used in networking, specifically in the context of configuring Open Shortest Path First (OSPF) routing on a router
network [ip-address] [wildcard-mask] area [area-id]	This command specifies which interfaces will participate in OSPF and to which area they belong
ip ospf [ospf id] area [area id]	used to configure the OSPF routing protocol on an interface. It specifies which OSPF process (identified by the OSPF ID) will be associated with a particular OSPF area (identified by the area ID) for that interface.
default-information originate	Configures the router to advertise a default route in OSPF
end	exit configuration mode.
exit	exits one level in the menu structure command.

Lab Task:

On R1 and R2 configure the LAN interface with the appropriate interface description, IPv4 address settings, and enable the interface. Perform in-flight checks.
Initiate a ping from PC1 to PC2 and from PC3 to PC4 the ping should be successful, if not then troubleshoot the issue before proceeding.
On all Routers check the WAN interface encapsulation, what command should you use? What is the default encapsulation used in Cisco Routers?
On all routers configure all WAN interfaces to use PPP encapsulation. Perform in-flight checks.
Across all WAN interfaces configure the appropriate interface description, and IPv4 address settings. In addition, create a loopback 0 interface for each device, please refer the IPv4 address table. Perform in-flight checks.
Create an OSPF ID of 1 on R1 and advertise 10.1.3.0/30, 1.1.1.1/32 and 192.168.10.0/24 networks. Use area 0.
Create an OSPF ID of 2 on R2 and advertise 10.2.3.0/30, 2.2.2.2/32 and 192.168.20.0/24 networks. Use area 0.
Create an OSPF ID of 3 on R3 and advertise 10.1.3.0/30, 3.3.3.3/32 and 10.1.3.0/30 networks. Use area 0.
Perform in-flight checks, across all Routers issue the appropriate command to:
1. Reveal the current IP protocol used
2. Display information about the OSPF process running
3. Reveal the current interfaces that operate in OSPF area 0
4. List the OSPF neighbor table
5. Display the OSPF Database
6. Display the routing table, can you see all network listed from the topology? If not, then troubleshoot the issue.
Perform connectivity tests between PC1, PC2, PC3 and PC4, all end devices should have full connectivity, if not then troubleshoot the issue.
Save your configuration.

Lab Solution:

1- On R1 and R2 configure the LAN interface with the appropriate interface description, IPv4 address settings, and enable the interface. Perform in-flight checks.

On R1:
R1#configure terminal
R1(config)#interface gigabitEthernet 0/1
R1(config-if)#description “Link to SW1”
R1(config-if)#ip address 192.168.10.254 255.255.255.0
R1(config-if)#no shutdown
R1(config-if)#end
R1#

On R2:
R2#
R2#configure terminal
R2(config)#interface gigabitEthernet 0/1
R2(config-if)#description “Link to SW2”
R2(config-if)#ip address 192.168.20.254 255.255.255.0
R2(config-if)#no shutdown
R2(config-if)#end
R2#

In-flight checks:

2- Initiate a ping from PC1 to PC2 and from PC3 to PC4 the ping should be successful, if not then troubleshoot the issue before proceeding.

On PC1 we were able to ping the default gateway and PC2:

On PC3 we were able to ping the default gateway and PC4:

3- On all Routers check the WAN interface encapsulation, what command should you use? What is the default encapsulation used in Cisco Routers?

We should issue this command “show interfaces [interface id]”
On R1:

On R2:

On R3:

Based on the output shown above, we can see that interfaces serial 0/3/1 and 0/3/0 are using HDLC encapsulation. Please watch the video for more information on the different types of encapsulations.

4- On all routers configure all WAN interfaces to use PPP encapsulation. Perform in-flight checks.

On R1:
R1#configure terminal
R1(config)#interface serial 0/3/1
R1(config-if)#encapsulation ppp
R1(config-if)#end
R1#

On R2:
R2#
R2#configure terminal
R2(config)#interface serial 0/3/0
R2(config-if)#encapsulation ppp
R2(config-if)#
R2(config-if)#end
R2#

On R3:
R3#
R3#configure terminal
R3(config)#interface serial 0/3/1
R3(config-if)#encapsulation ppp
R3(config-if)#interface serial 0/3/0
R3(config-if)#encapsulation ppp
R3(config-if)#
R3(config-if)#end
R3#

In-flight checks:

On R1:

On R2:

On R3:

You can see from the output above that the encapsulation has changed to PPP.

5- Across all WAN interfaces configure the appropriate interface description, and IPv4 address settings. In addition, create a loopback 0 interface for each device, please refer the IPv4 address table. Perform in-flight checks.

On R1:

R1#configure terminal
R1(config)#interface serial 0/3/1
R1(config-if)#description “Link to R3”
R1(config-if)#ip address 10.1.3.1 255.255.255.252
R1(config-if)#no shutdown
R1(config-if)#exit
R1(config)#interface loo
R1(config)#interface loopback 0
R1(config-if)#ip address 1.1.1.1 255.255.255.255
R1(config-if)#end
R1#

On R2:

R2#configure terminal
R2(config)#interface serial 0/3/0
R2(config-if)#description “Link to R3”
R2(config-if)#ip address 10.2.3.1 255.255.255.252
R2(config-if)#no shutdown
R2(config-if)#exit
R2(config)#interface loopback 0
R2(config-if)#ip address 2.2.2.2 255.255.255.255
R2(config-if)#end
R2#

On R3:

R3#configure terminal
R3(config)#interface serial 0/3/1
R3(config-if)#description “Link to R1”
R3(config-if)#ip address 10.1.3.2 255.255.255.252
R3(config-if)#no shutdown
R3(config-if)#interface serial 0/3/0
R3(config-if)#description “Link to R2”
R3(config-if)#ip address 10.2.3.2 255.255.255.252
R3(config-if)#no shutdown
R3(config-if)#exit
R3(config)#interface loopback 0
R3(config-if)#ip address 3.3.3.3 255.255.255.255
R3(config-if)#no shutdown
R3(config-if)#end
R3#

In-flight checks:

On R1:

On R2:

On R3:

6- Create an OSPF ID of 1 on R1 and advertise 10.1.3.0/30, 1.1.1.1/32 and 192.168.10.0/24 networks. Use area 0.

R1#
R1#configure terminal
R1(config)#router ospf 1
R1(config-router)#network 10.1.3.0 0.0.0.3 area 0
R1(config-router)#network 192.168.10.0 0.0.0.255 area 0
R1(config-router)#network 1.1.1.1 0.0.0.0 area 0
R1(config-router)#end
R1#

7- Create an OSPF ID of 2 on R2 and advertise 10.2.3.0/30, 2.2.2.2/32 and 192.168.20.0/24 networks. Use area 0.

R2#configure terminal
R2(config)#router ospf 2
R2(config-router)#network 10.2.3.0 0.0.0.3 area 0
R2(config-router)#network 192.168.20.0 0.0.0.255 area 0
R2(config-router)#network 2.2.2.2 0.0.0.0 area 0
R2(config-router)#end
R2#

8- Create an OSPF ID of 3 on R3 and advertise 10.1.3.0/30, 3.3.3.3/32 and 10.1.3.0/30 networks. Use area 0.

R3#
R3#configure terminal
R3(config)#router ospf 3
R3(config-router)#network 10.1.3.0 0.0.0.3 area 0
R3(config-router)#network 10.2.3.0 0.0.0.3 area 0
R3(config-router)#network 3.3.3.3 0.0.0.0 area 0
R3(config-router)#end
R3#

9- Perform in-flight checks, across all Routers issue the appropriate command to:
a. Reveal the current IP protocol used

b. Display information about the OSPF process running

c. Reveal the current interfaces that operate in OSPF area 0

d. List the OSPF neighbor table

e. Display the OSPF Database

f. Display the routing table, can you see all network listed from the topology? If not, then troubleshoot the issue.

10- Perform connectivity tests between PC1, PC2, PC3 and PC4, all end devices should have full connectivity, if not then troubleshoot the issue.

PC1 can ping PC3, and vice versa:

PC2 can ping PC3 and PC4:

11- Save your configuration.

Troubleshooting steps:

Here’s a comprehensive list of troubleshooting steps for the lab titled:

Verify VLAN Configuration on Switches:
- Command: show vlan brief
- Description: Check that the correct VLANs (VLAN 10 and VLAN 20 on SW1 and VLAN 30 and VLAN 40 on SW2) are configured and assigned to the appropriate interfaces.
- Troubleshoot: Ensure the PCs are connected to the correct VLANs by verifying their switch port assignments.
Check Sub-interface Configuration on Routers (R1 and R2):
- Command: show running-config | section interface
- Description: Ensure the sub-interfaces on R1 and R2 are correctly configured with the appropriate VLAN tags and IP addresses.
- Troubleshoot: Confirm that the encapsulation dot1q command is used with the correct VLAN ID and that each sub-interface has an assigned IP address.
Verify OSPF Neighbor Adjacencies:
- Command: show ip ospf neighbor
- Description: Verify that OSPF neighbor adjacencies are forming between R1, R2, and R3. The state should be “FULL” for successful adjacency.
- Troubleshoot:
  - If no adjacency forms, check IP addressing on the OSPF interfaces.
  - Ensure OSPF is enabled on the correct interfaces and in the correct area.
  - Verify that the OSPF network types are compatible (e.g., point-to-point or broadcast).
  - Ensure interfaces are not mistakenly assigned to different OSPF areas.
Check OSPF Process and Area Configuration:
- Command: show ip protocols
- Description: Review OSPF configurations, including the router ID, area, and network statements.
- Troubleshoot:
  - Ensure all routers are using the same OSPF area (Area 0 in this case).
  - Verify that the correct network ranges are included in the OSPF configuration using the network command.
Verify OSPF Routing Table Entries:
- Command: show ip route ospf
- Description: Ensure that OSPF-learned routes are appearing in the routing table of R1, R2, and R3.
- Troubleshoot:
  - If routes are missing, check OSPF neighbor relationships and ensure all interfaces are correctly included in the OSPF process.
  - Verify that OSPF is advertising the correct networks and that there are no filtering issues.
Test Inter-VLAN Connectivity Between PCs:
- Command: ping
- Description: Test end-to-end connectivity between PCs in different VLANs (e.g., PC1 in VLAN 10 to PC3 in VLAN 20).
- Troubleshoot:
  - If the ping fails, check the sub-interface IP configuration on the router for the corresponding VLAN.
  - Verify that OSPF is correctly propagating the inter-VLAN routes.
  - Ensure that PCs have correct IP addresses, subnet masks, and default gateways.
Check Interface Status and IP Configuration:
- Command: show ip interface brief
- Description: Confirm that all interfaces, including sub-interfaces, are in the “up” state and have the correct IP addresses assigned.
- Troubleshoot:
  - If an interface is down, check cable connections or port configurations.
  - Ensure the interfaces are correctly assigned to the OSPF process.
Verify Switch Port Modes:
- Command: show interface switchport
- Description: Ensure that the switch ports connected to the routers are operating in trunk mode, allowing VLAN traffic to pass through.
- Troubleshoot:
  - If trunking is not configured, issue the switchport mode trunk command on the appropriate interfaces.
  - Confirm that the correct VLANs are allowed on the trunk using the switchport trunk allowed vlan command.
Ensure Correct Default Gateway on PCs:
- Command: ipconfig (on Windows) or ifconfig (on Linux)
- Description: Verify that PCs have the correct default gateway corresponding to the router sub-interface IP address for their VLAN.
- Troubleshoot:
  - If the default gateway is incorrect or missing, manually configure it on the PC with the correct IP address of the router’s sub-interface.
Verify Trunk Configuration Between SW1 & R1, and SW2 and R2:
- Command: show interface trunk
- Description: Ensure that the link between SW1 and R1 is configured as a trunk and that the correct VLANs are allowed across it.
- Troubleshoot:
  - If VLAN traffic is not passing, check the trunk configuration and ensure that VLANs 10 and 20 are allowed on the trunk link on SW1. Similarly, with VLAN 30 and 40 are allowed on the trunk link on SW2.
  - Confirm that spanning tree or other Layer 2 issues are not blocking the trunk ports.
Check OSPF Timers and Hello Packets:
- Command: debug ip ospf hello
- Description: Check if OSPF hello packets are being sent and received between routers.
- Troubleshoot:
  - If hello packets are not exchanged, verify that OSPF timers (hello and dead intervals) are consistent on all routers.
  - Ensure Layer 2 connectivity between OSPF neighbors is functioning properly.
Ensure Correct OSPF Network Types:
- Command: show ip ospf interface
- Description: Verify that OSPF network types (e.g., broadcast, point-to-point) match the actual physical setup of the interfaces.
- Troubleshoot:
  - Mismatched network types can cause adjacencies to fail or routes not to propagate correctly. Set the appropriate OSPF network type with the ip ospf network command.
Review OSPF Debug Information (If Necessary):
- Command: debug ip ospf events
- Description: Use OSPF debug commands to gather more detailed information about OSPF events and issues.
- Troubleshoot:
  - Debugging OSPF events can reveal issues with neighbor formation, route propagation, and OSPF-related events. Use this as a last resort and analyze the debug outputs carefully.
Analyse Packet Flows with Traceroute:
- Command: traceroute
- Description: Use traceroute to identify where traffic may be getting dropped in the path between VLANs.
- Troubleshoot:
  - If the traceroute fails at a specific hop, investigate that device for issues related to routing, OSPF adjacencies, or interface configuration.

Hints and Tips:

Ensure Proper OSPF Area Configuration:
1. All routers participating in OSPF must be in the same area (in this lab, it’s likely to be Area 0, the backbone area).
2. Verify that all routers have the correct OSPF area assigned to their interfaces using the network command.
Check Interface IP Addresses:
1. Ensure that the correct IP addresses are assigned to each router interface. Incorrect IPs can prevent OSPF adjacencies from forming.
2. Use show ip interface brief to verify the interfaces’ IP addresses and status.
Wildcard Mask Configuration:
1. When adding networks to the OSPF process, remember that OSPF uses wildcard masks, which are the inverse of subnet masks. For example, a subnet mask of 255.255.255.0 will have a wildcard mask of 0.0.0.255.
Router IDs Must Be Unique:
1. OSPF Router IDs (RID) must be unique across the network to form adjacencies. If necessary, set the RID manually with the router-id command in OSPF configuration mode.
Check for Mismatched OSPF Timers:
1. Ensure that OSPF hello and dead timers are consistent across adjacent routers. You can check the timer values with show ip ospf interface. If timers are mismatched, OSPF adjacencies won’t form.
OSPF Neighbor State:
1. Verify OSPF adjacencies using show ip ospf neighbor. The state should be FULL for successful adjacencies.
Point-to-Point vs. Broadcast Networks:
1. Make sure OSPF network types are correctly configured based on the topology. For point-to-point links, manually set the network type using the ip ospf network point-to-point command, if necessary.
Ensure No Passive Interfaces:
1. OSPF will not send hello packets on passive interfaces. Check for any interfaces set as passive using the show ip ospf interface command. If needed, remove the passive setting with no passive-interface under OSPF configuration mode.

Conclusion:

In this lab, you have configured OSPFv2 on point-to-point links between routers, verified neighbor adjacencies, and ensured full route propagation.

The OSPF network type was set to point-to-point, optimizing the protocol for direct links between routers, as commonly used in WAN or dedicated link setups.

You also practiced troubleshooting common issues with OSPF neighbor formation and route advertisement.

This lab covers key skills for the CCNA 200-301 exam, particularly Objective 3.4.b, and prepares you for more complex OSPF deployments in enterprise networks.

Packet Tracer Lab (Pre/Post configuration):

Download the file below and open the word document to access the Packet Tracer labs.

CCNA 200-301 Lab Chapter 3 IP Connectivity Lab 033 Configure & Verify OSPFv2 Point-to-point – Pre and Post Labs Download