New posts might not happen for a while. I have changed jobs and the new job has nothing to do with Cisco. This leaves me with little time for studies. I have put too much time and effort into my Cisco studies to stop them now but the regularity of updates and the pace of work will not be like it was before.
OSPF develops neighbour relationships with routers on the same link by exchanging hello messages (a.k.a hellos).
At the initial exchange of hellos, the routers add each other to their respective Neighbour Tables (The Neighbour Table in this case acting as a list of connected OSFP enabled routers).
OSPF Enabled Routers send multicast hellos with a destination address 224.0.0.5 on all OSPF-enabled interfaces.
OSPF sends out hellos every 10 seconds on a broadcast link (a link with more than 2 nodes on the same segment like Ethernet) and 30 seconds on a non-broadcast (a link with only 2 nodes on the same segment; exceptions *shrug* exist for NBMA) link.
The Hello message contains:
After the initial hello exchange between two routers, an exchange of network information begins. After routers have synchronized their information they are adjacent.
Routers must go though various states from the initial relationship “hello” that transitions through a process before forming a “full” adjacency as shown above in the picture.
Once a full adjacency is achieved, tables between routers must be kept updated to prevent loops and routing errors. LSAs are re-sent when a change occurs, or every 30 minutes to keep routing information “fresh”.
Going through the different “states” a neighbour relationship can be in:
- Down - This is the first OSPF neighbour state, this state means that no hellos (information) has been received from any neighbour(s).
- Attempt - This state is only valid for manually configured neighbours in a Non-broadcast multi access (NBMA) environment. In Attempt state, the router sends unicast hellos every poll interval to the neighbour from which hellos have not been received within the dead interval.
- Init - This state indicates that the router has received a hello packet from its neighbour, but the receiving router’s ID was not included in the hello.
- 2-way - This state indicates that the bi-directional communication has been established between two routers
- Exstart - Once the Designated Router (DR) and Backup Designated Router (BDR) are elected, the actual process of exchanging link-state information can start between the routers and their DR and BDR.
- Exchange - In this state, OSPF routers exchange database descriptor (DBD) packets.
- Loading - In this state, the actual exchange of link-state information occurs.
- Full - In this state, routers are fully adjacent with each other. All the routers and networks LSAs are exchanged and the router databases are fully synchronized.
Hellos between routers continue to be sent periodically and the adjacency is maintained as long as hellos are exchanged. Missing hello messages result in a router declaring the adjacency being declared dead.
As soon as OSPF identifies a problem, it modifies its LSAs accordingly and sends the updated LSAs to the remaining neighbours (with full adjacencies).
Being event-driven, this LSA process intrinsically improves convergence time and reduces the amount of information that needs to be sent across the network.
A key piece of information exchange in LSAs is the OSPF metric information. Many OSPF vendors assign each link a cost of 10, Cisco makes cost inversely proportional to a 100 Mbs
An Admin can override the default cost. This would be done for compatibility reasons (with other OSPF speakers or because the link is more than 100 Mbps).
Sometimes the meric is equivalent for multiple paths to a destination. In this case, OSPF will load balance over each of the equivalent interfaces. Cisco routers will automatically perform equal-cost load balancing for up to four paths, but this parameter can be increased by configuration to as many as sixteen paths.
The cost is applied to the outgoing interface. The routing process will select the lowest cumulative cost to a remote network.
Notes and Notices:
This is a part of my personal BSCI notes and research to assist myself in learning and understanding the concepts and theory for the BSCI exam. I learn by making notes reading and writing things down and wish to file them where I can’t lose them. These notes are not to be seen, judged or mistaken for replacements to Cisco recognized and authorized training which I personally support and attend and suggest you undertake if you are going for the BSCI Certification.
Cisco Live! is the Cisco annual ‘Networkers’ conference. For the first time ever the will be held in Sandton, Johannesburg on 1st – 4th December 2008. Cisco Live! will be the place for network engineers from all over Africa gather for technical training, education and networking. For the past eleven years, the conference has been at the forefront of educating delegates on new technologies.
The Cisco Live! conference will incorporate a new concept ‘Networkers at Cisco Live!’ with a mix of technical and business offerings. This format broadens traditional technical focused meet-ups to include executive tracks that examine the role of technology in driving business value in a challenging economic climate. The theme of this year’s conference is ‘The Power of Collaboration’ and delegates can look forward to thought-provoking keynotes from local and international Cisco executives and industry experts.
Networkers at Cisco Live! will be held at the Sandton Convention Centre and will attract more than 1,500 delegates, making it the largest Networkers conference in South Africa to date. The program will comprise various sessions, ranging from technical trainings to an invitation-only executive symposium. Delegates will also have the opportunity to view the World of Solutions demonstration area, which will showcase collaboration and communication tools and technology, such as TelePresence.
A Word from Steve Midgley the Managing Director of Cisco South Africa
“South Africa is the first country outside the United States to introduce the Cisco Live! brand. With Cisco Live!, we are taking the event to the next level to provide a platform where industry players can learn new technologies, discuss business trends, share ideas and network,” said Steve Midgley, Managing Director, Cisco Systems South Africa.“In recent years, specialization, globalization and new technologies have resulted in more collaborative environments made up of global, virtual networks and communities that improvise and find more productive, innovative and faster ways to do business. Cisco puts communications and collaboration capabilities within the context of a business process to allow workers increase their productivity, speed and agility,” added Midgley.
Speakers
Rick Hutley, vice president of Global Innovations for Cisco Internet Business Solutions Group, will be a keynote speaker at the event. Hutley, responsible for engaging Cisco’s largest global customers, will discuss the role of collaborative technologies in addressing the key business challenges and opportunities faced by organisations today.
Also speaking at the conference will be World Wide Worx’s Arthur Goldstuck, who will present findings from the Cisco-sponsored Internet Access in South Africa 2008 research report. Goldstuck’s presentation will cover the latest trends in Internet access and will set the scene for a discussion around the future of connectivity in South Africa, which plays a crucial role in collaboration.
For more information on Networkers at Cisco Live! www.networkersafrica.co.za
Open Shortest Path First (OSPF) is an open standard routing protocol, defined in detail in many Internet Engineering Task Force (IETF) Request For Comments (RFCs)Â including RFC 2328.
OSPF uses the Shortest Path First (SPF) Algorithm to calculate the best path to a given destination. OSPF builds loop-free paths that converge quickly, but often requires more processor power and memory than distance vector routing protocols (EIGRP).
OSPF can be more complicated because there are many topology and configuration options to consider versus EIGRP that has is has less of a learning curve.
OSPF is designed to offer flexibility in network design (OSPF is an open standard vs EIGRP that is Cisco Proprietary) which IOW allows OSPF to supports linking between different vendors Cisco, HP, etc.
OSPF Basics
OSPF as mentioned before is a Link-State routing protocol (basics) that is based on the Dijkstra Shortest Path First (SPF) Algorithm.
When one compares distance-vector routing to link-state routing;
- link-state routing processes more information locally (on the router meaning more memory & CPU use) to reduce network bandwidth use.
- Link-State routing protocols record all possible routes thus avoiding many of the techniques needed by distance-vector routing protocols to avoid loops.
- Distance-vector routing protocols advertise routes to neighbours while link-state routing protocols advertise a list of connections.
- In link-state routing, a neighbour is a directly connected router (or a router on the opposite side of a WAN link with the same network address).
OSPF is used within an Autonomous-System (AS). It has advantages over distance-vector routing protocols:
- OSPF is classless + allows summarization
- Converges quickly
- OSPF is a standard, and fairly widely support can be found in a heterogeneous environment
- Conserves bandwidth
- uses multicast and not broadcast
- sends incremental change-based updates
- uses cost as the metric
- KB is fairly widely available and less restricted than EIGRP
When a link goes up or down in a link-state routing protocol network, a link-state advertisement (LSA) is generated. LSAs are shared with neighbours and a topological database (a.k.a link-state database (LSDB) or Topology Table) is built.
LSAs are marked with sequence numbers so that older and/or newer versions of advertisements can be recognized (start 0×8000 0001 end 0xFFFF FFFF before rolling to the start again). The eventual goal is that all routers in the same AS has the same LSDB which is then processed using SPF from which the best routes are selected and a routing table created.
The Topology Database (LSDB) is the routers view of the network within the AS it operates. This includes every OSPF router within that area and all connected networks.
To view the current status of the link state database,
Router#show ip ospf database
The Topology Database is updated by LSAs and each router in a AS has exactly the same topology database. All routers must have the same view of the network otherwise routing loops or loss of connectivity will occur.
When a router realizes there has been a change to the network topology, the router is responsible for informing the rest of the routers in the area with a LSA. This happens mostly due to:
- A router losing physical or data-link layer connectivity on a connected network
- A router does not receive a predetermined number of consecutive OSPF hello messages
- A router receives a LSA update from a adjacent neighbour, informing it of the change in the network topology
In any of the above cases, the router will generate an LSA and flood it to all neighbours with the following stipulations:
- If the LSA is new, the route is added to the database, the route is flooded out other links so other routers are updated, SPF is rerun.
- If the sequence number is the same as the current entry in the Topology Database, the router ignores the advertisement.
- If the sequence number is older, the router sends the newer copy (in memory) back to the advertiser to make sure that all neighbours have the latest LSA.
All OSPF operations centre around populating and maintaining
- Neighbour Table
- Topology Table
- Routing Table
Notes and Notices:
This is a part of my personal BSCI notes and research to assist myself in learning and understanding the concepts and theory for the BSCI exam. I learn by making notes reading and writing things down and wish to file them where I can’t lose them. These notes are not to be seen, judged or mistaken for replacements to Cisco recognized and authorized training which I personally support and attend and suggest you undertake if you are going for the BSCI Certification.
So finally South Africa is treated to the bright, amazing, and wondrous release of the Applie iPhone 3G (totally missing out on Version 1), that’s unless you had a cousin, connection or friend in another “more developed” country smuggle one in for you. I would have been there on the launch day (I like the vibe of launch days) but I was quad biking in the bushveld (sun, wild animals, 4×4 lots of fun and first holiday in a long time).
Here is the laugh though; since the launch (a week ago today) I have seen 1 (total) being used (at a Fortinet mixer last night). I have decided against being a South African first adopter becuase of articels like this and this and don’t want to be find out first hand how bad Vodacom support can be on a new product.
I stopped into a Voda-store (local reseller) to have a listen to the whole story on a “Apple package deal” and was thoroughly disgusted as they wanted me to sign “another contract” on top of the one I already have. I had to ask three times specifically NO CONTRACT ONLY HANDSET before I was told that the Voda-super-store was the only place that sold iPhone out-of-hand for the super price of ZAR 7,569. These sharks don’t tell you when you ask, or listen when you ask and con people into signing contracts for 24 months onto existing 24 month contracts. Totally Disgusting this being one of their resellers and how they operate. Probably why Vodacom South Africa has a Net Profit of ZAR 8 Bn and Earnings before interest, taxation, depreciation, amortisation, impairment, profit/loss on disposal of property, plant and equipment, investment properties, intangible assets and investments of ZAR 16.5 Bn.
Today on MyBroadband they had a nice piece on the cost of the iPhone in other markets versus here.
Anyone want that iPhone 3G with added Apple Tax all things considered? Seems a little much for me taking into consideration what it says on the box isn’t what the product seems to be doing all over the world.
So while I am working diligently at getting back into the Cisco swing of things with my study notes and Cisco Press books and making posts on a regular basis (this is happening just slowly OSPF is beating me up left, right and centre). This all after some added work commitments and other stuff has been sorted out.
This came in a Cisco email today and I really enjoyed it. Good for a laugh or two. These cubicle jockeys are somewhat athletic compared to the ones I know.
Something on the vine I found that was interesting. I really think this kind of thing should be done more often and with more fanfare by Associations and Large Companies with access to Statistics where abuse of a “public” system is prevalent.
The SPAM hall of shame from Internet Service Providers Association (ISPA) lists the Top 5 SPAM generators in South Africa. These boys and girls are probably mild compared to their international counterparts but still in a local view attempting to manage SPAM this may help some.
I’m bogged down at the moment with HP Partnership Management work and haven’t been making posts on Network Ninja (never mind touch CCNP books or get organized with putting my LAB together) so don’t feel left out if you feel I have been neglecting updating, I feel like I am running backwards fast on getting my CCNP done.
I haven’t had time for anything else either like seeing clients, making sales, doing installations or even going into the office 
(I’m not really complaining all that much about the last one). I’ve moved my “office” to my house and for the time being haven’t seen any other room but my Study and Bedroom. Teleworking is really the bomb, rolling out of bed and getting straight to work suits me just fine (for a while) I kind of like separating my home and work life when it gets down to it.
I did however break my self inflicted work isolation to attend the brief for the new collaboration portfolio hosted by Christopher Thompson, Senior Director for Solutions Marketing at Cisco via Telepresence (ooooh!! very nice kit this). This was the first time I was actually in the room attending a meeting using the Cisco Telepresence (above) solution, while Chris was in Europe we were in South Africa and let me tell you, when I grow up one day I am getting one of these! My web cam just doesn’t cut it any more. A little off-topic, I did a post on Telepresence a while ago and I did say that everyone should organize a Demo for themselves (Call Cisco and ask) because let me tell you impressive does not cover this solution, its really amazing!
After the meeting ended we chatted with Chris for a while and he mentioned that by Friday (that is Friday 26th not next Friday) he will have done 300 presentations to Press and other parties all over the world on the Collaboration Portfolio. Imagine the cost savings Cisco realised in one week by doing these Telepresence meetings versus sending multiple people like Chris (Senior Director mind you) all over the world to do these briefings for the pre-launch? AND This is just one event and they do this all the time!
I am going to say again to any Corporate or Mid-sized company that is interested in Telepresence to cut down travel costs for meetings where they have multiple locations either nationally or internationally. Organise a demo by calling Cisco or a local Partner you won’t look back. Back to the topic.
Collaboration
The concept of Collaboration in the workplace (Also during Degree Training at Universities) has been a hot-topic for a while and many vendors (IT or not) have positioned product, services and bundled solutions at this space because of its “importance” in $$$ terms. Whether these products are new and engineered to meet this need or old re-boxed marketing/advertising spins is another topic for another day.
The importance of Collaboration cannot be discounted however as maximizing the ease, effectiveness and efficiency of communication, sharing, meetings and abilities inter- and intra-company drives higher return on investment per project as more can be done, more effectively, in less time, with more ease, without the need of any re-work and no-work because of crossed-wires and misunderstanding.
Collaboration with Cisco
The Cisco Collaboration Portfolio is designed and engineered to work with you like you work. That’s whether you are 20 or 50 the CEO or the Grad Student doing the coffee run. Cisco realises that people, companies, and age groups are different and they have modeled an open solution portfolio set to suit the way in which individual companies work and the individuals in the company like to work.
The solution will work even in mixed deployment environments where Microsoft, Linux, OSX and others play as it was made to be operating system independant. There is deeper linking with vendors like IBM and Microsoft (if that matters). The portfolio scales from small to super-size by being either hosted on demand (SaaS) or mixed hosted and on-premises or totally on-premises. The portfolio will help accelerate business processes, increase productivity and speed innovation by bringing people together and helping them work more efficiently and effectively together.
The Portfolio consists of Unified Communications, Video (Telepresence) and new Web 2.0 applications platforms all of which leverage the network as a platform to enable people to connect, communicate and collaborate from ANY WORKSPACE (Microsoft, Apple, Linux and even Smartphones) without degradation of service of a change of experience.
The Portfolio works the way you do and is designed to integrate with business applications, existing IT infrastructure and other web services (If it has an API it can integrate examples Goolge, Flickr, Salesforce), allowing developers and partners to develop and create customized applications and network based services.
The Portfolio includes some of the following key products and solutions:
Cisco Unified Communications Release 7.0
Cisco Unified Communications System Release 7.0 enables collaboration so that organisations can quickly adapt to market changes and improve competitive advantage through speed and innovation. Accelerating the deployment of unified communications requires the ability to leverage existing infrastructure and applications.
It offers enhancements to its applications development environment and provides deeper integration with desktop products from IBM and Microsoft. Mobility enhancements extend productivity features across every workspace.
Cisco Unified Mobile Communicator now supports devices running on Windows Mobile as well as Symbian and Blackberry with support for Apple iPhone coming soon. Cisco UC Release 7.0 continues to drive down system and management costs by increasing Cisco Unified Presence scalability to 30,000 users and Cisco Unity to 15,000 users on a single server and by optimizing network management through an easy-to-use appliance deployment environment.
Cisco TelePresence Expert on Demand
Cisco TelePresence Expert on Demand integrates Cisco Unified Communications and Cisco Unified Contact Center with the immersive “in person” experience of Telepresence to transform the way organisations deliver high-touch customer and point of sale services.
It enables customers to connect with subject-matter experts for tailored, in-person service at the touch of a button. This gives users the ability to summon expert assistance directly in a Cisco TelePresence meeting or use a dedicated customer-facing Cisco TelePresence endpoint and get face-to-face assistance.
An organisation can choose to configure Cisco TelePresence Expert on Demand with a direct assistance number, a hunt group, or its Cisco Unified Contact Centre deployment. In the latter case, a user will be connected to an appropriate agent via skills-based routing.
Cisco WebEx Connect
Cisco WebEx Connect is a cloud-based application platform for collaborative business mashups. It includes a number of standard applications including enterprise instant messaging, team spaces, document management, calendaring and wikis, which can be combined with third party widgets built using open APIs, enabling companies to work from a single workspace. Extensive administrative controls support enterprise policy, security and compliance requirements to enable highly secure inter-company collaboration.
WebEx Connect works with Cisco Unified Communication system to deliver seamless communication capabilities within the context of a collaborative mash-up.
More Information:
Cisco Unified Communications 7.0
Thanks
Thanks goes out to JP and Jonathan for the Invite to the Brief.
So yesterday it became official that Cisco Systems, Inc. is going to be investing ZAR 215,000,000 in South Africa (USD 27,000,000) love the naughts makes it looks like REAL money. The investment will go to the Cisco Innovation Hub Technology Centre (CIHTC) that will be become the home of Information and Communication Technology (ICT) initiatives including an InnovationLab, a global Talent Acquisition Programme, the Cisco Netversity, an Entrepreneur Institute and a Software Development Programme.
This investment is expected to collectively drive a R1bn gross domestic product (GDP) effect over an initial five year period. The 3000 square metre CIHT Centre will be based at the Innovation Hub (accross the CSIR) in Pretoria, South Africa.
The CIHTC complex will be an advanced tech incubation centre aimed at fostering and developing local skills, intellectual property, entrepreneurship and solution development capabilities in the ICT sector. The implications of this is 200 direct and 800 indirect employment opportunities and development of intellectual property, the training and certification of design and network engineers, local software development, state of the art network communication laboratories (maybe even CCIE and practice labs, hold thumbs!!!!), access to business guidance and a showcase for venture capital providers looking to fund solutions or businesses that result from Centre Operations.
In the words of Steve Midgley, Managing Director of Cisco South Africa “South Africa is on the brink of entering a broadband boom,” which in turn will “change the way people live and work – giving the public sector and business the opportunity to gain significant efficiencies, to drive productivity enhancements, to achieve cost reductions and to gain access to new market segments within their existing business models. It will also create an enabling platform from which new business models can be created. Cisco is investing in this initiative now to ensure that when the broadband revolution really kicks off, South Africa has enough of the right kind of skills, solutions creation capabilities and intellectual property to leverage the many benefits broadband will bring to the country.”
About a two weeks ago David Bombal from Configure Terminal contacted me about doing a write up for CCIE Command Memorizer. As a current CCNP student there is obviously some of the CCIE content that still goes over my head but most of the stuff I am fairly okay with. David didn’t seem to mind that I wasn’t a CCIE as yet and I sure didn’t mind giving CCIE Command Memorizer a spin so below are my thoughts and feelings.
During my initial research on the CCIE Command Memorizer I found that CCIE Command Memorizer was geared towards the CCIE Routing and Switching (R&S) Lab. When I received the application Monday two weeks ago my initial impression was that it covers without many frills and spills in an effective and efficient manner the commands in a Do-It-Yourself fill in the blanks task to objective orientated format. There is no round-about, search for things “what now” moments; everything is straight and to the point. Another bonus is that the download isn’t enormous either.
The CCIE Command Memorizer application itself is written in an e-book format, which works for the content and in that format. If like myself you like using the keyboard when you get going on command line (IOW dislike moving between the mouse+keyboard) some of the shortcuts might feel “off” and take a bit to get use to. Take heart that once you get going it all starts flowing like second nature.
My feelings on how the CCIE Command Memorizer would fit into my studies it that as a study tool / study aid as it helps you practice commands anywhere at any time as long as you have your notebook handy (face it as a CCNP I realize I am a Geeks and my notebook goes on holiday with me so this pretty much means anywhere). My current situation with a LAB is that I am busy getting racks, cabling, and other kit together to put a LAB up, the actual LAB is non-existent. In my situation the CCIE Command Memorizer is my stop-gap for actual “command” time practice as I don’t really have kit and at times no block time to zero in on a specific Technology Area and do some quick revision work with a specific focus only on that technology. This is different from the LAB where you need to setup and configure peripheral services and technologies to get to the meat close to the bone, CCIE Command Memorizer lets you focus ONLY on those parts to give you practice on those parts.
In my opinion students that would find the CCIE Command Memorizer useful would be individuals who have problems with instant recall of information when under stress or duress (people with classic test condition issues that forget as they walk through the door when in normal day-to-day they are Uber networkers) and students who need to drill things to remember (repetition, repetition, repetition) information to get it to pass from short term into long term memory (this one would be me). Most other students may also find it handy to bridge the book theory and lab practical (where you just went through the theory to quickly go over the practical again to cement the knowledge just a bit more).
From my perspective as a CCNP student the CCIE Command Memorizer shares most (if not all) of the content material with the CCNP that I cared to check up on. In the two weeks I have been working through EIGRP and OSPF (notes to follow shortly) for the BSCI. Everything I covered in theory the CCIE Command Memorizer covered + some more.
To close off for those who want a one-size-fits-all study solution don’t mistake the CCIE Command Memorizer for something it wasn’t built to be. The CCIE Command Memorizer is a STUDY TOOL / STUDY AID and not a “Complete Blended Solution” or All-In-One (aio) Product like the guys from IP Expert offer. This will mean that you will probably either attend classes from a Cisco Learning Partner and/or do labs at home or through a Rack Rental Company and/or also have Cisco Press books that will ADD TO THE VALUE the CCIE Command Memorizer.
In summation I suggest taking a serious look at the CCIE Command Memorizer and how to integrate it into your study plans. Taking all things into consideration I would seriously recommend the CCIE Command Memorizer even to current CCNP level students. The value add is easy to find and it helps to have something that you can take along as you travel that does command line study effectively without the need to spend hours on “setting up other things” before you get to play with advanced topics.