Latest Blog
08December 2015
HSRP – VRRP – GLBP
HSRP, VRRP and GLBP are the three commonly used first hop redundancy protocols in local area networks and the data center. In this post, I will briefly describe them and highlight the major differences. I will ask you a design...
08December 2015
January 2016 Online CCDE Bootcamp
I have just decided to schedule my next online class for the February 2016 CCDE Practical exam preparation because of three reasons. One is the high level of demand for my early CCDE bootcamps; the other is the overwhelming number...
07January 2016
MANET: Mobile Ad Hoc Networks
The MANET stands for mobile ad hoc network; in practice, the term generally applies to ad hoc wireless networks of sufficient complexity that some internal routing mechanism is needed to enable full connectivity. (more…)
24January 2016
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...
11February 2016
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...
22February 2016
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. (more…)
17April 2017
April Online CCDE Class is going to start today
I am excited as today, 2017 CCDE April Online (Webex) class is going to start. Actually , there is only half an hour and we will start. Every day will be 4 hours and minimum 11 days it will take....
08May 2017
May 2017 Dubai CCDE Bootcamp Attendees Feedbacks !
Dubai 5 days Instructor Led Bootcamp just finished. Attendees were from Spain, Bahrain , Saudi Arabia, India and Abu Dhabi. (more…)
17May 2017
Some people who passed the exam on FEB 2017 lost their CCDE !
As you know May 11 2017 exam has been cancelled. I shared the details in this post. Cisco took very hard decision but saved the CCDE certification. I have been suggesting that new scenarios should be added for a long...
16July 2017
Free Knowledge Sharing Group for Service Providers !
Recently I initiated a knowledge sharing group on Slack. Goal of the group is just a knowledge sharing. What technologies, protocols, equipments are other people using in the in their networks, what are their services , what are their paint...
29July 2017
Moved to new house , Finished the new course but !
I have been very busy for last one month. I announced 2 , 3 months before Service Provider Design Workshop and conducted it at last two weekends. I moved to new house, lot's of things to deal with,...
07August 2017
Did you see my Networkcareer.net Interview?
I recently made an interview with networkcareer.net I talked with Daniel many things on networking, brief overview of my story , predictions for the future of networking, recommended community platforms for the network engineers and many other things ! (more…)
12August 2017
Very important update on CCDE Practical Exam Result !
As you might know May 2017 exam was cancelled due to leakage and I shared a post on it on May. It was very important step taken by Cisco to secure the exam. Now, it seems another important...
14August 2017
New design of www.orhanergun.net
I used to receive many queries on design of website and we did few changes. (more…)
21August 2017
Network Interconnection videos have been added into Self Paced SP Training
Recently, I published Self Paced Service Provider Training Course. I didn't make an Internet wide announcement yet as I still upload the content to the course. (more…)
24August 2017
Last 5 days for the August 2017 CCDE Practical/Lab exam
Last 5 days anymore for the August 2017, CCDE Practical/Lab exam. (more…)
31August 2017
What are the changes in August 2017 CCDE Practical exam ?
What are the changes in 2017 CCDE Practical/Lab exam ? (more…)
04September 2017
Istanbul/Turkey Onsite CCDE Training – 5
Istanbul/Turkey Onsite CCDE Training will be held between October 30 - November 4. Course will be in English as usual, everyday will be between 9am - 6pm, 9 hours. I am going to extend my CCDE Materials for...
30October 2017
LDP retention and distribution modes
MPLS protocol uses labels to forward traffic between point A and B. These labels are binded to FECs and distributed on the network by means of different protocols like (LDP, RSVP, BGP-LS, SPRING). LDP (Label Distribution Protocol "RFC5036") is still...
15November 2018
Intent Based Networking , Is it the next big thing ?
Nowadays there are some technologies which every vendor talk about. SD-WAN is very hot topic but another one is Intent Based Networking. (more…)
16November 2018
Segment Routing and MPLS VPN
MPLS VPN and Segment Routing. Many people have been asking what are the differences between MPLS VPN and Segment Routing. (more…)
20November 2018
Network Discovery and Mapping
What is Network Discovery and Mapping? As networks are growing and getting more dynamic, mapping and documenting the devices that are connected to our network will be harder and much time consuming. I know paper work and the network documentation...
Success Stories
Orhan goes into a great level of detail to explain the design implications of each technology and the relationships with other technology that it could affect.
Michael Zsiga
Lead Architect at ePlus
I passed the CCDE Practical exam and Orhan’s CCDE course was very important contributor to my success.
Daniel Lardeux
Senior Network Consultant at Post Telecom
Orhan’s ability to cover the vast technical topics required for the CCDE is tremendous. He is not only very technical; he is also an amazing teacher.
Jason Gooley
System Engineer at Cisco Systems
I attended Orhan’s CCDE Course and I must say the guy has exceeded my expectations in all ways in terms of quality, depth etc.