Solved

Differentiate single-area OSPF from multi-area OSPF?

Posted on 2016-09-02
3
23 Views
Last Modified: 2016-09-22
Differentiate single-area OSPF from multi-area OSPF?
0
Comment
Question by:Marilyn Navarro
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
3 Comments
 
LVL 30

Accepted Solution

by:
Predrag earned 250 total points (awarded by participants)
ID: 41782575
Beside all other differences you can identify it easy by issuing:

# sh ip ospf database

Single-area OSPF will have only LSAs from Area 0 (and maybe external)
Router Link States (Area 0)
Net Link States (Area 0)
Type-5 AS External Link States
The first two you will find in every area

Multi-area OSPF will have more LSA types (but at least will have more area numbers) :)
Router Link States (Area 0)
Net Link States (Area 0)
Summary Net Link States (Area 0)
Summary ASB Link States (Area 0)
Router Link States (Area X)
Net Link States (Area X)
Summary Net Link States (Area X)
Summary ASB Link States (Area X)
Type-5 AS External Link States

OSPF Link state advertisements
0
 
LVL 1

Assisted Solution

by:Ranti
Ranti earned 250 total points (awarded by participants)
ID: 41782959
The reason why people create multiple areas in OSPF is to divide the network map before it gets too big. OSPF uses Link State routing protocol which use Open Shortest Path first. So each router has the whole map of the network.
Now if the network grows too big it gets slower and slower. So in many organisation, the architect's usually create new areas when the network grows more than 60-70 routers.
Basically in ospf network, every area need to have one router thats an Area Boarder Router(ABR) which is connected to the area0. Now there are exception to this rule, when people create virtual links. In my opinion, that only a work around and should not be implemented unless really necessary.

So in Summery, single area you only have one area, which is area 0, every router has a route map. When area grows bigger and bigger network architects create multiple areas and summarise the ip address from one area and advertise to another area.
0
 
LVL 1

Expert Comment

by:Ranti
ID: 41810368
Covered the base differences.
0

Featured Post

[Live Webinar] The Cloud Skills Gap

As Cloud technologies come of age, business leaders grapple with the impact it has on their team's skills and the gap associated with the use of a cloud platform.

Join experts from 451 Research and Concerto Cloud Services on July 27th where we will examine fact and fiction.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

I recently attended Cisco Live! in Las Vegas, a conference that boasted over 28,000 techies in attendance, and a week of hands-on learning hosted by a solid partner with which Concerto goes to market.  Every year, Cisco displays cutting-edge technol…
For months I had no idea how to 'discover' the IP address of the other end of a link (without asking someone who knows), and it drove me batty. Think about it. You can't use Cisco Discovery Protocol (CDP) because it's not implemented on the ASAs.…
After creating this article (http://www.experts-exchange.com/articles/23699/Setup-Mikrotik-routers-with-OSPF.html), I decided to make a video (no audio) to show you how to configure the routers and run some trace routes and pings between the 7 sites…
Sending a Secure fax is easy with eFax Corporate (http://www.enterprise.efax.com). First, just open a new email message. In the To field, type your recipient's fax number @efaxsend.com. You can even send a secure international fax — just include t…

623 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question