In this article I want to emulate a real DSL connection; that is called PPPoE connection. You know that the DSL technology has become very popular nowadays. So knowing the basics of this technology is a must for every network engineer. In this small article, I will establish a PPPoE connection between two Cisco routers, one has the role of PPPoE Aggregation Server and another as a normal Client. Most of home users are using their xDSL Modem as their PPPoE client, but there are small DSL modems that have not this capability and therefore, you can use your PC as PPPoE client. (for example, you can create a PPPoE connection on Windows/Linux PCs to turn your PC to a PPPoE client.)

In this small article I want to talk about a basic scenario of AToM. the MPLS protocol can be used to encapsulate other L2 protocols, like Ethernet, PPP, HDLC, etc and transport them across MPLS backbone that is owned by an SP. now let's try the first one, that is HDLC or PPP over MPLS. for this purpose imagine we have this network in hand:

I was working a simple RIP scenario between 3 routers that are connected serially (R1 to R2 to R3) and want to test “ip rip triggered” command between R2 and R3. In the meantime, I turned on the debug feature about RIP on R2 and R3 to analyze the events. On the other hand, R1 had some loopback interfaces with IP addresses in range 1.0.0.0/8 range. I configured RIP summarization On R1 so R2 and R3 can have just major network of 1.0.0.0/8 in their routing tables. I realize that R1 just send summarization to R2 and R2 does not pass the summary to R3. Then I turned off auto-summarization on R2 too, so R3 can have summarized route of 1.0.0.0/8. The interesting part which make me post this topic was that, after some changes occurred on routers (cause I was in the middle of practicing!), R3 lost its RIP routes and reachability to other networks and even the output of debug commands (even debug ip packet command) was completely empty! That means nothing transferred between R2 and R3 at all! Finally an error message displayed on R3 as follows:

*Mar  1 01:50:07.359: RIP: Removing everything from x.x.x.x's retrans queue and stopping the retrans timer.

After investigating the RIP protocol configs on R2 and R3, I saw the triggered feature put the “timers basic 30 180 0 240” command on the RIP routers (R2 and R3). I changed the timers, so holddown timer got value of 180, but nothing happened. At the end, I removed RIP configurations on R3 and then reentered them again on R3 as a final solution. That worked and everything went ok! I don’t know that was because of GNS bug or IOS that I used, but was a strange behavior of RIP routers that I want to publish ;)

This is short post about connecting to Cisco devices with SSH. some people asking me to talk about this and this is the solution. We have this simple topology:

If you want to connect to Cisco Devices using SSH bidirectionally, you must execute these commands on 2 routers.

At the third part of this document, we are going to redistribute RIP routes inside OSPF domain. First of all I’m going to test the R2 and R3 reachability to 66.66.66.66/32 (loopback interface on R6).

R2(config-router)#do ping 66.66.66.66
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 66.66.66.66, timeout is 2 seconds:
.!!!!
Success rate is 80 percent (4/5), round-trip min/avg/max = 8/22/36 ms

R3(config-router)#do ping 66.66.66.66
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 66.66.66.66, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 16/33/68 ms

this is a nice and good poster about Cisco certification status and deserves to look it. http://www.ine.com/cisco-careers-infographic.htm

CCIEs with more that CCIE

As I remember, I have always surprised and actually motivated when I see someone that has managed to do everything great; like fighting alone with a crowed! meanwhile, getting a certificate like CCIE or JNCIE is very difficult too and need passing very hard times besides sacrificing some valuable things. So I decide to list here so e names that did such a great job, holding 5 or 6 CCIE or JNCIE together! Good luck for all of them and hope they get even more!

1. Neil Moor, CCIE #10044 (RS, SP, Sec, Voice, Storage, Wireless) and many more!

2. Tarun Pahuja, CCIE #7707 (RS, SP, Sec, Voice, Storage, CCSI) and many more!

3. Khawar Butt, CCIE #12353 (RS, SP, Sec, Voice, Storage, CCDE, CCSI) and many more!

4. Brian Dennis, CCIE #2210 (RS, SP, Sec, Voice, ISP dial) and many more!

5. Scott Morris, CCIE #4713 (RS, SP, Sec, ISP dial, CCDE) and JNCIE-ER #102 and JNCIE-SP #153, plus many more!

6. Petr Lapukhov, CCIE #16379 (RS, SP, Sec, Voice, CCDE)

7. Iwan Hoogendoorn, CCIE #13084 (RS, SP, Sec, Voice)

8. Jorg Buesink, CCIE #15032 (RS, SP, Sec, CCDE), JNCIE-SP #284, JNCIE-ENT #21, JNCIE-SEC #30

9. Tom Glennon, CCIE #3263 (RS, ISP Dial, WAN, SP, Sec)

10. Dmitry Bokotey, CCIE #5531 (RS, ISP-Dial, Security, SP, Storage)

11. Michael Crane, CCIE #5531 (RS, Security, SP, Voice, Storage)

12. Richard Davis, CCIE #5672 (RS, SP, Security, Voice, Storage)

13. Mason Harris, CCIE #5916 (RS, SNA IP, ISP-Dial, SP, Security)

13. Takanori Matsui, CCIE #7664 (RS, SP, Security, Storage, Voice)

14. Chang-Min Kim, CCIE #12303 (RS, SP, Security, Voice, Storage)

15. Yoshinori Okayama, CCIE #14795 (RS, Voice, Security, SP, Storage)

16. Michael Purcell, CCIE #4110 (RS, ISP-Dial, SNA-IP, Security, SP, Voice)

17. Noritaka Tamehisa, CCIE #4699 (RS, Security, SP, Voice, Storage,Wireless)

18. Roman Rodichev, CCIE #7927 (RS, Security, Voice, Storage, SP, Wireless)

19. Matthew White, CCIE #14533 (RS, Security, Voice, Storage, SP, Wireless)

20. Mike Crane, CCIE #5531 ( RS, Security, Voice, Storage, SP)

21. Fabien Degouet, CCIE #6684 (RS, Security, Voice, Wireless , SP)

22. Shahzad Ali, CCIE #7466 ( RS, Security, Voice, Storage, SP)

I'll add more names as I find later. besides, you can get relatively complete list in here.

Recently I realized that, one of my best friends and famous instructors, Mr. Farshid Makoui managed to pass his 3rd CCIE in Cisco Brussels Exam Center. it is interesting to say that he is pursuing his 4th CCIE (that will be Security) and has booked it now! so we can see him proudly holding 4 CCIEs.  congratulations to him and hope to see him among CCAr elite group as soon as possible.

Cisco has introduced the mobile lab program to provide candidates greater access to Lab testing while greatly reducing travel time and expenses. Mobile CCIE Labs provide a convenient and cost-effective method for candidates to test for CCIE Routing and Switching and CCIE Security in areas which do not have permanent lab locations.

Junosphere Classroom.

Juniper has introduced the new product for students or companies which want to educate their employees that extremely decrease the overall cost to learn the Jonus. This platform is a unique service offered from the Junosphere cloud, Junosphere Classroom enables you to cost-effectively educate students, employees, or partners on the principles and operation of Junos OS, routing protocols, and networking in general. Junosphere Classroom allows you to create virtual networking labs that provide students with full hands-on access to Juniper's commercial networking technology, without the expense of building or maintaining your own physical lab.
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