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OSPF Area Types

OSPF Area Types – Different Areas in OSPF are used to create smaller fault domains.There are totally two OSPF area types. OSPF Backbone area and OSPF non backbone area. Backbone area in OSPF is Area 0. OSPF prevents loop by using backbone area concept.All the non-backbone areas should be connected to the Backbone area. There are […]

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Pim Sparse Mode

Pim sparse mode – Multicast is used to send the data to the multiple receivers at the same time. Multicast reduces the load on the servers (Senders/Source in multicast term), provides efficient capacity usage on the network links. Figure – 1 Unicast vs Multicast Flows Multicast runs on top of UDP. Multicast uses Class D […]

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Enjoy the DesignWorld Subscription Discount before the 5-day Deadline

Hello Everyone As you all know, the DesignWorld is a place where you can find network design videos, articles, quizzes, and comparison charts. Currently, only CCDE resources are there, but the good news is that other courses will be added, too. In addition, CCDA and CCDP courses will be added. There was a promotion for the […]

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OSPF LSA Types

OSPF LSA (link state advertisements) are used to create a logical network topology. But Why we have 11 different LSAs ? What are their purposes ? Most important questions many time is not asked by the engineers thus you can’t find many places on the Internet which provides these answers. The reason of having 11 […]

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MPLS Design Case Study

MPLS Design – MPLS Design Case Studies are the useful resources to learn the design details of MPLS. You will be provided a brief information about the business and technical requirements. You can share your answer at the comment section below. Note: This is only one of the case studies in the DesignWorld. DesignWorld provides […]

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April 2016 CCDE Bootcamp

CCDE Bootcamp – This is an Online Cisco CCDE exam preparation training. Probably you all know the success of Orhan Ergun’s CCDE Bootcamps and how it has been helping so many engineer become a better network engineer/designer. If you don’t know, please just take a tour on the website. Check the Success Stories, Why Orhan and […]

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BGP Design Case Study

Below BGP design case study is taken from the Orhan Ergun’s CCDE Practical Workbook.In the new version of the workbook there are more than 50 case studies are shared for many technologies. If you are in the network design field or want to learn about it,don’t miss the book. Scenario : Network A is a customer […]

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WHY YOU SHOULD PLACE LESS EMPHASIS ON MPLS TRAFFIC ENGINEERING

If I input MPLS traffic engineering on any search engines, I will find about 100 articles on the internet providing the same explanations about MPLS traffic engineering. But unfortunately, nobody ask these questions: do I really need it? What are the reasons behind the implementation of MPLS Traffic Engineering? Would it worth the time and energy […]

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Segment Routing Fast Reroute

Segment Routing Fast Reroute  – Traffic Engineering with Segment Routing uses LFA mechanism to provide 50 msec fast reroute capability. Current Segment Routing implementation for the OSPF uses regular LFA (Loop Free Alternate) for fast reroute in Cisco devices. Because LFA (Loop Free Alternate) has topology limitations, it does not include many faulty scenarios. On the […]

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Segment routing key points

Segment Routing  (SR) leverages the source paradigm. A node. steers a packet through an ordered list of instructions, called ‘ segment ‘.State is kept in the packet header, not on the router, with Segment Routing.

Resources such as the CPU and Memory are saved.

If you have 100 Edge Routers in your network and if you enable MPLS Traffic Edge to Edge, you would have 100×99/2 = 4950 LSP states on your Midpoint LSR. This is prevalent in many MPLS TE enabled network.

If you enable Segment Routing and if you evaluate the same midpoint case (since you assign a Prefix/Node SID for every Edge router), Midpoint LSR would have 110 entries instead of 4500 entries.

As for the scalability, everything is perfect. However, there is a caveat.

Segment list can easily get big if you use explicit routing for the purpose of OAM. If you do that, you may end up with 7-8 segments. In that case, it is pertinent that you check the hardware support.

Cisco claims that they have performed the tests on a number of service provider networks and that their findings show that two or three segments would be enough for the most explicit Continue reading

Your design should be usable !

Whatever you design , it should be usable first. Computer network design is not an exception.You are not designing a network to support one service only such as VPN or Internet.It should provide enough functionality for today and future needs. Your design should be usable today and the future ! It was so common to use… Read More »

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