So we're moving into the more advanced OSPF topics and at the outset of this, we're going to talk a little bit about OSPF network types on NBMA which is Non-Broadcast Multi Access. Now you'll recall we talked a little bit about NBMA networks when we talked about EIGRP. Unfortunately unlike EIGRP which just kind of works if you've got a, the broadcast keyword set up on your Frame Relay Network. OSPF has a few different network types and a few different network configurations and you have to kind of know what to expect when you're going through them. OSPF actually has five types of network topologies when it comes to NBMA networks. Three are RFC standards and two are Cisco Proprietary. Now hopefully I don't have to point out that Cisco Proprietary Network topologies for OSPF require all Cisco routers, but I'll, I'll point it out anyway because you wouldn't believe the number of people that don't know the definition of the word Proprietary. We'll start off talking about the RFC standard type of networks and then we'll move onto the Cisco Proprietary Networks and in the lab which we'll do immediately following this slide show, we'll set up a multi-area OSPF network using three different types of network topology and you'll get to see all of them in action. The first RFC standard type of topology we're going to talk about is Broadcast. Now Broadcast is pretty much like what it sounds. It's the default for Ethernet, it's any type of network topology where you can actually send broadcasts. The Broadcast type network topology uses a Designated Router and a Backup Designated Router and all of the routers just kind of find one another. You saw it when we set up our basic OSPF Setup back when we did the first lab, you know, we just configured OSPF on the right interfaces and the neighbor relationships formed and, and away we go. Now by far it is the simplest and technically Point-to-Point networks use Broadcast to find their neighbors, but Point-to-Point is actually different RFC standard and we'll talk about it here in just a couple of minutes, but just know that Broadcast type networks are used when they're all on the same Ethernet segment. The next type of RFC standard network type we're going to talk about is Non-Broadcast and if Broadcasts just kind of work, you can imagine that Non-Broadcasts don't just work by themselves. Non-Broadcast network type is default for Multi-point Interfaces or Frame Relay Interfaces. The Non-Broadcast RFC standard still uses a DR and a BDR because again on these Multi-point Interfaces your WAN network is basically one big layer three network, however, since you can't send broadcasts across these networks, you have to use Manual Neighbor Statements to get OSPF up and running. You have to go into the hub of your hub and spoke router or into one of your hub and spoke routers and say, there's my manual neighbors and we'll set that up when we set up our lab here in just a few minutes. Now it's important to know that even if you use the Broadcast Keyword on your Frame Relay Interfaces when you're setting up your Frame Relay Maps for example, because it is on a Multi-point Interface, OSPF is going to say, well I can't use broadcasts and it's not going to use broadcasts and you can go in and force it to use broadcasts but we, we won't do that because, well then it's just kind of too easy, I mean, come on, where, where's the challenge in that? So carrying on with our RFC standard, the third type of RFC standard network is a Point-to-Point network and you'll recall where we talked about Broadcast Networks and how they just all kind of work. Point-to-Point Networks pretty much kind of work too, it's the default for all the Point-to-Point protocols, HDLC, PPP are Frame Relay Point-to-Point. If OSPF sees that configured as your network type, then it will automatically default to the Point-to-Point Network. The Point-to-Point Network does not use a DR or a BDR and if you'll recall from our discussions of what the DR and BDR actually does, you'll recall that on a Point-to-Point Network, it's not really needed. There's only two nodes on the link so I mean, yeah, you can be the DR and be the BDR, I'll be the DR and you can be the BDR, doesn't really matter because when one router sends a broadcast across the Point-to-Point to link to find it's neighbor, of course, it's going to find it and you know, there's, there's no flooding possible there like there would be on an Ethernet network. So now we'll move into the Cisco Proprietary Network types and it's really two variations of the same type of Cisco Network. That is Point-to-Multipoint broadcast and Non-Broadcast. And I kind of lumped them together because they pretty much act the same, the only difference between the two is one can pass broadcasts and one can't but OSPF still doesn't pass broadcasts even if the Multi-point topology supports it. For the Point-to-Multipoint broadcast or Non-Broadcast Networks, say that five times fast, it is used on Frame Relay Partial Mesh Networks and you'll recall the Partial Mesh is where you don't have every network where they can talk to every other network but most of your networks talk like this. It does not use a DR or a BDR either because again, every network can talk to every other type of network and again you also have to use Manual Neighbor Statements as you would in the Non-Broadcast type of network. And that's it, it's pretty simple and we'll see all of these network types in use in our lab, but for now that concludes our discussion of the OSPF network types on NBMA.
TERMS & CONDITIONS OF USE
BY SUBSCRIBING TO THIS SERVICE, YOU ARE CONSENTING TO BE BOUND BY AND ARE BECOMING A PARTY TO THIS AGREEMENT, THE TERMS AND CONDITIONS OF WHICH SHALL PREVAIL IN GOVERNING YOUR RIGHTS OF USE. BY CLICKING THE "BECOME A MEMBER" BUTTON, THE INDIVIDUAL OR ENTITY LICENSING THE PRODUCT ("YOU") IS CONSENTING TO BE BOUND BY AND IS BECOMING A PARTY TO THIS AGREEMENT. IF LICENSEE DOES NOT AGREE TO ALL OF THE TERMS OF THIS AGREEMENT, THE BUTTON INDICATING "BECOME A MEMBER" MUST NOT BE SELECTED, AND LICENSEE MUST NOT INSTALL OR USE THE SOFTWARE.
"VTC" refers to Virtual Training Company,
"You" refers to the user or subscriber.
"Software" refers to the VTC training content and software.
2. LICENSE: VTC hereby grants to You a worldwide, non-royalty bearing, non-exclusive license to use the Software according to the provisions contained herein and subject to payment of the applicable subscription fees.
3. RESTRICTIONS: You may not do any of the following:
Save the Software to Your hard disk or other storage
medium; permit others to use the Software except as specified by addendum;
modify, reverse engineer, decompile, or disassemble the Software; make
derivative works based on the Software; publish or otherwise disseminate
the Software. VTC, Inc., VTC Online University, and the Virtual Training
Company site is owned and operated by VTC, Inc. as a corporation of
All materials on this site are the property of VTC unless otherwise specified. No material from these pages may be copied, reproduced, republished, downloaded, uploaded, posted, transmitted, or distributed in any way. Modification of the materials or use of the materials for any other purpose is a violation of U.S. copyright law and other proprietary rights. For purposes of this Agreement, the use of any such material on any other web site or networked computer environment is prohibited.
4. FEES: The rights granted under this Agreement
are effective only upon payment of the subscription fees, which are
strictly non-refundable other than as expressly provided herein. The
term "monthly subscription" is defined as any 30 day period.
The term "yearly subscription" is defined as one 365 day
period. A yearly subscription ends on the same numerical date as it
began (example July 28, 2004 to July 28, 2005).
The VTC Online University is access to every VTC training tutorial in our library. You pay a flat fee for access to these titles. You are billed according to your renewal selection below, and can renew monthly, yearly, or in any other increment offered. If you choose to be billed monthly, you will be billed every 30 days for the subscription until you request the subscription be cancelled. Our terms of service state that you must cancel a monthly subscription at least two business days before your renewal date. These two days give us enough time to ensure that you will not be charged again.
5. LIMITED WARRANTY: VTC warrants that the Software, if operated as directed, will substantially achieve the functionality described. VTC does not warrant, however, that Your use of the Software will be uninterrupted or that the operation of the Software will be error-free or secure. In addition, the security mechanisms implemented by the Software have inherent limitations, and You must determine that the Software sufficiently meets Your requirements. VTC also warrants that the media containing the Software, if provided by VTC, is free from defects in material from the date You acquired the Software. VTC's sole liability for any breach of this warranty shall be, in VTC's sole discretion: (i) to replace Your defective media or Software; or (ii) to advise You how to achieve substantially the same functionality with the Software as described; or (iii) if the above remedies are impracticable, to refund the subscription fee You paid for the Software. Only if You inform VTC of Your problem with the Software during the applicable subscription period will VTC be obligated to honor this warranty. VTC will use reasonable commercial efforts to repair, replace, advise, or refund pursuant to the foregoing warranty within thirty (30) days of being so notified. If any modifications are made to the Software by You during the warranty period; if the medium is subjected to accident, abuse, or improper use; or if You violate the terms of this Agreement, then this warranty shall immediately terminate. This warranty shall not apply if the Software is used on or in conjunction with hardware or software other than the unmodified version of hardware and software with which the Software was designed to be used as described.
THIS IS A LIMITED WARRANTY, AND IT IS THE ONLY WARRANTY MADE BY VTC OR ITS SUPPLIERS. VTC MAKES NO OTHER WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND NONINFRINGEMENT OF THIRD PARTIES' RIGHTS. YOU MAY HAVE OTHER STATUTORY RIGHTS. HOWEVER, TO THE FULL EXTENT PERMITTED BY LAW, THE DURATION OF STATUTORILY REQUIRED WARRANTIES, IF ANY, SHALL BE LIMITED TO THE ABOVE LIMITED WARRANTY PERIOD. MOREOVER, IN NO EVENT WILL WARRANTIES PROVIDED BY LAW, IF ANY, APPLY UNLESS THEY ARE REQUIRED TO APPLY BY STATUTE NOTWITHSTANDING THEIR EXCLUSION BY CONTRACT. NO DEALER, AGENT, OR EMPLOYEE OF VTC IS AUTHORIZED TO MAKE ANY MODIFICATIONS, EXTENSIONS, OR ADDITIONS TO THIS LIMITED WARRANTY.
6. PROPRIETARY RIGHTS: VTC reserves all proprietary rights in and to the Software, is protected by copyright and other intellectual property laws and by international treaties. VTC, Inc.
Trademark Notice: VTC, Virtual Training Company,
Inc., The VTC Logo, and VTC Online University, are trademarks of VTC,
Inc. All other company and product names may be trademarks of their
The information contained herein is subject to change without notice. Copyright © 1995 - 2005 VTC, Inc. All rights reserved.
7. TERMINATION: This Agreement shall automatically terminate if You fail to comply with the restrictions described herein. Your obligations to pay outstanding subscription fees shall survive any termination of this Agreement.
8. LIMITATION OF LIABILITY: UNDER NO CIRCUMSTANCES
AND UNDER NO LEGAL THEORY, TORT, CONTRACT, OR OTHERWISE, SHALL VTC
OR ITS SUPPLIERS OR RESELLERS BE LIABLE TO YOU OR ANY OTHER PERSON
FOR ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES OF
ANY CHARACTER, INCLUDING WITHOUT LIMITATION, DAMAGES FOR LOSS OF GOODWILL,
WORK STOPPAGE, COMPUTER FAILURE OR MALFUNCTION, OR ANY AND ALL OTHER
COMMERCIAL DAMAGES OR LOSSES. IN NO EVENT WILL VTC BE LIABLE FOR ANY
DAMAGES IN EXCESS OF THE AMOUNT VTC RECEIVED FROM YOU FOR A LICENSE
TO THE SOFTWARE, EVEN IF VTC SHALL HAVE BEEN INFORMED OF THE POSSIBILITY
DAMAGES, OR FOR ANY CLAIM BY ANY OTHER PARTY. THIS LIMITATION OF LIABILITY SHALL NOT APPLY TO LIABILITY FOR DEATH OR PERSONAL INJURY RESULTING FROM VTC'S NEGLIGENCE TO THE EXTENT APPLICABLE LAW PROHIBITS SUCH LIMITATION. SOME JURISDICTIONS DO NOT ALLOW THE EXCLUSION OR LIMITATION OF INCIDENTAL OR CONSEQUENTIAL DAMAGES, SO THIS EXCLUSION AND LIMITATION MAY NOT APPLY TO YOU.
9. Links To Other Materials: Linked sites found at the VTC site are not under the control of VTC, and we are not responsible for the content of any linked site or any link contained in a linked site. VTC may change links based solely on our discretion, and we reserve the right to terminate any link or linking program at any time. VTC does not, by linking to sites, endorse companies or products to which it links and reserves the right to note as such on its web pages. If you decide to access any of the third party sites linked to this site, you do this entirely at your own risk.
Forums, and Chat are not always screened by VTC, and we are not responsible for the content of any public or open forum content at the site. VTC may change these public forums based solely on our discretion, and we reserve the right to terminate any forum at any time. VTC does not, by allowing these forums, endorse companies or products which may be mentioned in these forums, and reserves the right to note as such on its web pages. If you decide to access any of the public forums in this site, or linked to this site, you do this entirely at your own risk.
9. GOVERNING LAW & DISPUTE RESOLUTION: This Agreement is governed by Virginia law. All disputes between You and VTC shall be finally resolved through arbitration in Winchester, Virginia. This site is controlled by VTC from its offices within the United States of America. VTC makes no representation that materials in the site are appropriate or available for use in other locations, and access to them from territories where their content is illegal is prohibited. Those who choose to access this site from other locations do so on their own initiative and are responsible for compliance with applicable local laws. You may not use or export the Materials in violation of U.S. export laws and regulations. Any claim relating to the Materials shall be governed by the internal substantive laws of the Commonwealth of Virginia, USA.
VTC may revise these Terms at any time by updating this posting. You should visit this page from time to time to review the then-current Terms because they are binding on you. Certain provisions of these Terms may be superseded by expressly designated legal notices or terms located on particular pages at this Site.
If you have any questions regarding this policy,
or your information specifically,
you may email us at:email@example.com.