Dec 08

OSPF Troubleshooting Steps


OSPF is a link-state protocol that gathers information from all the routers in the neighboring areas and chooses the shortest path with minimum cost for the data to be transmitted. It can successfully manage the bandwidth of the network and easily work on complex networks. However, sometimes issues may arise causing problems for data transmission in the shortest path. It is important to identify the issues and find proper methods to troubleshoot them. The common issues faced by OSPF and ways they can be troubleshot is mentioned below.

  1. OSPF Neighbor Issues: This issue arises if there is a connection problem between the two devices and the shortest path can’t be determined by OSPF. To troubleshoot, you need to check a few parameters like if the devices are in the same subnet, are in the same area, and have unique router IDs. Some of the commands mentioned below are used to troubleshoot.
  2. show ip protocols – This command is used to verify and troubleshoot the OSPF’s global configuration.
  3. show ip ospf – It verifies the basic configuration information related to OSPF protocol. The output shows information about Router ID, SPF related information, and Area related information that is useful.
  • show ip ospf interface – It can be used to see a particular interface or all interfaces configuration and check if it is participating in OSPF or not. It also provides other information such as –
  • Interface IP address
  • Which area the interface is connected to as they must be in the same area to establish a neighboring relationship.
  • Router ID of the interface must be unique.
  • The type of network
  • The Designated Router and the Backup designated router in that OSPF segment.
  • Hello and Dead timers
  • Adjacency reason in case of multi access networks
  1. show ip ospf neighbor – This command is used to show the neighbor related information and study the neighbor data structure.
  2. OSPF Routing Table Issues: This issue arises when some of the contents of the table get removed and OSPF can’t function properly. You need to identify if some of the routes have been deleted or damaged in the routing table an adjacency check will be required and external LSA check if any damage was made to external routes information.
  3. show ip ospf database – This command displays two important information. One is the area to which the route is connected to and the number of other routers present in that area. Second is the network links found in that area. It shows LSA types, Link ID, advertising router, and age.
  4. show ip route ospf – It shows OSPF routes that were received from the neighbors and information about it like administrative distances and cost.
  5. OSPF INIT Issues: When a router is able to send “Hello” messages to the neighbor but the neighbor is unable to return back the “Hello” it is known as the INIT state. So if this issue arises we need to check the authentication used in both the devices, the physical cabling, and also the switch settings. The following command is used to check the authentication.

show ip ospf interface – This command verifies if the same authentication keys are configured by both the devices.

  1. ACL Issues: Sometimes ACL interferes with the functioning of the OSPF and you need to check if any routers are configured with the ACLs. The following command is used to check.

show ip interface – This command verifies if ACL is applied to the specific interface to which OSPF is also configured. If ACL is found, then it needs to be disabled and check if OSPF has started to work again.

For More info Click here

Looking for an IT Job?

Please call us on 1800 159 151, or complete the form below.

  • This field is for validation purposes and should be left unchanged.

Recent Posts

Demand for Cybersecurity in Australia – How to learn cybersecurity?

Are you thinking of a career in cybersecurity? Do you wish to change your career to cybersecurity? Are you interested to learn cybersecurity? Are you.. Read More →

Can you get a job with just a CCNA certificate?

People often worry about getting jobs after acquiring a few years of education or a specific certificate. This is the exact situation with people who.. Read More →

Does a CCNA Certification help in getting Good Jobs?

The CCNA certificate will surely help you get in a better position right now. This certificate holds much power because of its course. It mainly.. Read More →

The supply of this course/package/program is governed by our terms and conditions. Please read them carefully before enrolling, as enrolment is conditional on acceptance of these terms and conditions. Courses run subject to registrations.


Find out why we are the leading choice to help boost your career in Australia

Prepare to get IT job ready in 8 weeks

Trained 10,000+ professionals and counting

Experienced Provider: Operating Since 2004

Trained staff from 1000+ Australian Businesses

We Have Placed Candidates In

Over 1000 organisations have relied on Logitrain to be their trusted training partner.

High-quality, cost-effective training in Australia
Learn More
  • OpenPay
  • This field is for validation purposes and should be left unchanged.

Dont’ Wait. Fill the form for a free no-obligation information session with our course specialists.

About The Author

Delivering Classroom and Live Virtual Training with Price Beat Guarantee

COVID discounts on Job Programs end soon, register today.