Got it

How to prevent loops in the OSPF backbone 0 area

Latest reply: Dec 29, 2018 08:04:43 1384 2 8 0 1

How to prevent loops in the OSPF backbone 0 area?

Routers in an OSPF autonomous system do not directly transmit routing information to maintain the routing table. They exchange link state information (LSA), and each router maintains a unified link state database.
Each router uses itself as the root node based on the LSDB information and calculates the link cost (cost) to obtain its own routing table.
Because the LSDB is consistent, no routing loop occurs.

Solution 1:
The loop does not need to be explained. Three connected equal areas or devices, A sends to B, B sends to C, and C sends a loop to A.

There are many ways to solve a loop, the most typical of which is this primary method.

STP also uses this method to maintain order and avoid loops.

The OSPF area is maintained by the AREA0.

Solution 2:
Do you think that all networks are connected to the backbone network and are forwarded by the backbone network? Can a loop be formed? The answer is not, but if the backbone network is not connected to the backbone network, a loop may occur.

Solution 3:
OSPF uses the SPF algorithm. The principle is that data can be forwarded to the destination only through the backbone area.

  • x
  • convention:

Created Dec 29, 2018 06:02:04

An OSPF network can be divided into areas that are logical groupings of hosts and networks. An area includes its connecting router having interfaces connected to the network. Each area maintains a separate link state database whose information may be summarized towards the rest of the network by the connecting router. Thus, the topology of an area is unknown outside the area. This reduces the routing traffic between parts of an autonomous system.

Areas are uniquely identified with 32-bit numbers. The area identifiers are commonly written in the dot-decimal notation, familiar from IPv4 addressing. However, they are not IP addresses and may duplicate, without conflict, any IPv4 address. The area identifiers for IPv6 implementations (OSPFv3) also use 32-bit identifiers written in the same notation. When dotted formatting is omitted, most implementations expand area 1 to the area identifier, but some have been known to expand it as
View more
  • x
  • convention:

Created Dec 29, 2018 08:04:43

Open Shortest Path First, which ensures that no loop occurs.
View more
  • x
  • convention:


You need to log in to comment to the post Login | Register

Notice: To protect the legitimate rights and interests of you, the community, and third parties, do not release content that may bring legal risks to all parties, including but are not limited to the following:
  • Politically sensitive content
  • Content concerning pornography, gambling, and drug abuse
  • Content that may disclose or infringe upon others ' commercial secrets, intellectual properties, including trade marks, copyrights, and patents, and personal privacy
Do not share your account and password with others. All operations performed using your account will be regarded as your own actions and all consequences arising therefrom will be borne by you. For details, see " User Agreement."

My Followers

Login and enjoy all the member benefits


Are you sure to block this user?
Users on your blacklist cannot comment on your post,cannot mention you, cannot send you private messages.
Please bind your phone number to obtain invitation bonus.
Information Protection Guide
Thanks for using Huawei Enterprise Support Community! We will help you learn how we collect, use, store and share your personal information and the rights you have in accordance with Privacy Policy and User Agreement.