Total 248 Blogs

Created by - Orhan Ergun

May CCDE Practical exam results have been announced. Student feedbacks in this post!

Hello, May 2019 CCDE Practical exam results were announced a few days ago. I am happy to help 4 people to have their CCDE numbers on May 2019 exam. Congrats to Matt, Fredrik, Dmytro, and Schilling for passing CCDE Practical exam. They received their numbers! Let me help you to get it now ! The next Webex CCDE Class will start in 10 days! You can see Webex-based CCDE Courses by clicking here You can see Onsite/In-Class CCDE Courses by clicking here I would like to share their testimonials with you. Hope to see you in one of my classes soon.! Matt Cross – Technical Architect at Heartland – CCDE #2019::7 Orhan did an excellent job of filling in the gaps of knowledge that I had that took me to the finish line of the practical exam CCDE. The community of people that Orhan facilitates is both engaging and supportive of the journey to CCDE. Orhan was always quick to answer any email or chat messages that I sent him. Overall I am very happy with the time spent engaged in the material and Bootcamp. Thanks, Orhan! DmytroOsmachka – CCDE #2019::10 Orhan, I came, I learned and now I got my CCDE number! For those who prepare for the CCDE Practical exam, all you need is some experience and Orhan’s guidance! Thanks, Orhan for all your support. Shiling Ding – Sentinel Technologies – CCDE #2019::12 Just passed the CCDE Practical exam! I attended Orhan Ergun’s CCDE training program and used Orhan’s Instructor Led and Self-Paced CCDE training and Online CCDE Practical Scenarios during my CCDE journey. Orhan’s CCDE In-Depth book is an excellent summary book about almost all topics related to CCDE. Orhan’s practical scenarios are well organized and discussions in his Webex are very valuable. Orhan also from time to time hosts Webex lectures on different technology topics, I find it’s another revenue to refresh and strengthen my understanding of different topics. Orhan’s study group is very active, different peers share their experiences, discussion, and insight on not only the CCDE but also different technologies. I surely appreciate Orhan’s excellent training materials, constant guidance, and demonstrated dedication to help me get CCDE. As always, life is a constant learning experience, and CCDE is only one of the small steps! Please be aware: Many people still are not aware that we have started CCIE SP training. In fact, some students already passed and I will try to announce them periodically. You can have a look at the details of CCIE SP training by clicking here CCIE SP and CCDE together provide operational and design experience, thus I recommend you to get Bundle CCIE SP and CCDE Course.  See you in one of the upcoming CCDE training! 

Published - Fri, 08 Nov 2019

Created by - Orhan Ergun

Recommended Networking Resources for September 2019 Second Week

There are so many good resources for Network Engineers out there. I started to share the ones I liked last week. Click here to see September 2019, First Week Networking Recommended Resources. As you know, I will share 5 resource every week. There are so many in my list already, I can’t wait for the next week to share next recommended 5 resources! Let’s start. This post is explaining the basics of Active-Active Datacenter concept. https://www.missioncriticalmagazine.com/blogs/14-the-mission-critical-blog/post/89161-architecting-for-activeactive-data-centers 2. BGP Information Security is very important to secure Global Internet. Origin Validation can be done in two ways, IRR and RPKI, Networks can have both at the same time. Below post explains RPKI (Resource Public Key Infrastructure) in very good detail. https://blog.cloudflare.com/rpki-details/ 3.  BIER (Bit Indexed Explicit Replication) is very cool new tool for scalable IP and MPLS Multicast Design. When I explain it in few words, I say, Segment Routing removes the requirement of LDP and RSVP for Transport LSP in MPLS, BIER does the same thing for Multicast Traffic. You don’t need PIM, mLDP etc. Below Packet Pusher podcast is all about BIER and couple other cool Datacenter specific Routing protocols (RFC 7938 type of Datacenter routing protocol) RIFT and BGP+SFC. PQ Show 115: BIER, RIFT & BGP+SFC At IETF 98 4. Is IPv6 faster than IPv4? Let’s try to understand what are the considerations IPv4 or IPv6 can be faster. Below APNIC post have some good statistics as well. Why is IPv6 faster? 5.  We have Flat Internet concept. Many large ASes exchange traffic in either Private or Public Peering with each other directly. Those networks are directly connected and their traffic is just one hop away. This effectively reduces average AS-Path length to 4 in Global Internet Routing Table (Commonly known as DFZ- Default Free Zone). Below research paper is explaining with a great analysis about Flat Internet paradigm and how networks are just one hop away mostly in today Internet.https://irtf.org/raim-2015-papers/raim-2015-paper20.pdf

Published - Fri, 08 Nov 2019

Created by - Orhan Ergun

Recommended Networking Resources for September 2019 Third Week

There are so many good resources for Network Engineers out there. I started to share the ones I liked on beginning of this month. Click here to see previous Networking Recommended Resources. As you know, I share 5 resource every week. There are so many in my list already, I can’t wait for the next week to share next recommended 5 resources! Let’s start. Below video is explaining different NAT concepts, specifically CGN (Carrier Grade NAT) and present some good statistics about usage of CGN in Mobile/Cellular Networks. 2. BGP Information Security is very important to secure Global Internet.  BGP Leaks effect potentially millions of users when it happens. Below post explains ‘What is BGP Route Leak’ , starting from ‘What is BGP’ and shows an example how by starting intentional Route Leak to steal crypto currency.  https://blog.cloudflare.com/bgp-leaks-and-crypto-currencies/ 3.  Nice video on SD-WAN at DKNOG. Explaining some technical details but mainly stay at the architectural level.  4. For those who are looking to understand Diffserv (Differentiated Services) Quality of Service Architecture, must read RFC 4594.  https://tools.ietf.org/html/rfc4594 5.  Today, most of the IP networks use PIM (Protocol Independent Multicast) when they have Multicast in their networks.Before PIM, DVMRP was deployed in many large scale networks. In the below video, GEANT (European Research Institute) explains how they deployed DVMRP and how they migrated from DVMRP to PIM, and the reasons for migration.

Published - Fri, 08 Nov 2019

Created by - Orhan Ergun

Recommended Networking Resources for September 2019 First Week

I would like to share with you every week some networking resources , can be video , article , book , diagram , another website etc. Whatever I believe can be useful for the computer network engineers, mobile network providers, satellite engineers ,transmission experts, datacenter engineers,  basically whatever I am interested in and I like, I will share in a blog post. There will not be any order of importance among the resources. You can open and go through anyone you want. I will try to limit the list with 5 resources as I want you to read the posts that I publish on the website. Sometimes can be more than 5 though! Let’s get started! TCP vs QUIC – Quic is a new transport protocol I think everyone should have a look at. What are the high level differences between them etc. TCP vs QUIC: A New Transport Protocol 2.  Below post explains how BGP As-Path prepending , when it is done more than couple times , can be dangerous for the attacks on BGP information security Excessive BGP AS-PATH prepending is a self-inflicted vulnerability 3.  This presentation is one of the best presentation about BGP Add-Path, or maybe it is not good to do Add-path. https://ripe60.ripe.net/presentations/Raszuk-To_add-paths_or_not_to_add-paths.pdf 4. In the below video, Randy Bush is talking about IPv6 Transition mechanisms and Operational reality of the different transition mechanisms. 5.  In the below white paper, you can have a look at recent enhancements in MPLS Traffic Engineering. Concept like RSVP- Multipath (TE++) is explained in the paper. http://www.sanog.org/resources/sanog27/SANOG27_Conference_RecentAdvancesInMPLS-TE.pdf If you would like to see more resources weekly, let me know in the comment box below. Whatever is your feedback, let us communicate in the comment section of the blog. Hope this will be useful for you! I love networking, I love helping people who like it!

Published - Fri, 08 Nov 2019

Created by - Orhan Ergun

Tech Field Day in Barcelona

I was in Barcelona last week, there was a Cisco Live as you might know. During the Cisco Live unfortunately I couldn't meet with people as I was invited them by Tech Field Day and recorded many great sessions together. Cisco announced ACI in Cloud and there was presentations about it. If you don't know the format of Tech Field Day, companies present their most recent innovations , technologies and group of experts ask the questions , share their comments during the presentations. Sessions are streamed live and recordings are shared on Tech Field Day youtube channel. Network verification, assurance and intent based networking is a hot topic in the industry and during TFDx (Tech Field Day Extra), Forward Networks presented their solution. In the verification area, there are couple serious vendors; IP Fabric and Forward Networks are two of them and I closely follow their latest enhancements. I have been supporting IP Fabric for some time and many times I shared my thoughts on social media (Mostly I use Linkedin) about them. If you are operating a network, especially medium or large scale networks, in order to reduce manual tasks , bring automation to your operation , reduce troubleshooting time , remove single point of failure from your network in a dynamic manner and many other important operational capability. I visited their booth at Barcelona Cisco Live 2019, and saw that many people were interested their solution. Cisco , Forward Networks and AVI Networks were the presenters in TFD 2019 at Barcelona and I enjoyed their presentations mostly, when there is no boring marketing slides. I recommend you to check Tech Field Day Youtube channel to watch the presentations. It was not only presentations I liked, but , as a city Barcelona was great too. Very clean and wide roads , respectful people , easy communication (okay not maybe with taxi drivers) were just couple good things I can tell you about Barcelona. I tried to eat Duck at dinner , and it was not a good experience though. Everyday we got the taxi from the Hotel to the convention center. If you don't know who are in the picture. Left to Right , Tom Hollingsworth , Orhan Ergun , Ivan Papeljnak. My taxi friends, usual suspects at Barcelona. Tom is a great guy, delivering Tech Field Day , Ivan is writing articles on ipspace.net and joining conferences , public speaking and author. I had a good times with them overall and looking forward for the next events. There was many other nice guys, expert in their fields (Virtualization , Security etc.) who were the delegate same as me, they are in the below picture. Last but not least, I will share my thoughts and some technical information for their products and the recent announcements of the companies which were in the TFDx 2019. Cisco , Forward Networks and AVI Networks.

Published - Fri, 08 Nov 2019