Apr
28
Thank you to all those who have submitted questions and comments to our blog and our CCIE Instructors. If you have a question, please email them to blog@ine.com. Question 1: Hi, Is it possible to recommend the Cisco press books to read when preparing for the Cisco SP Written exam. Kind Rages For the written exam, you should make sure you have reviewed the items in the online resources General, Metro Ethernet, and Service Provider sections for the Written Exam Blueprint preparation material.... Read More
Apr
25
Here ye, here ye, VTP experts. (We are not referring to the Vandenberg Test Program, although they are very likely experts in their field as well.  :)) Can you predict the results of a 3 switch VTP client/server scenario? SW1-3, are connected, as shown in the diagram. Here is the initial output of show VTP status, and show VLAN brief on each. Note that SW1 and SW3 are servers, while SW2 is a client.   We will be adding a failure to the network in just a moment. Read More
Apr
16
Thank you to all those who have submitted questions and comments to our blog.  We will be taking time each week to post answers to your questions and to post some of these comments.  If you have a question for one of our CCIE Instructors please email them to blog@ine.com. Question #1 Can anyone please advise what is the recommended laptop hardware configuration for CCIE R&S Lab prep. I have read many blogs, posts and advices but unable to figure out the appropriate answer. While advising,please... Read More
Apr
15
Sometimes its the simple things that are struggled with. RIP is one of those. Most CCIE candidates understand that we can change the interface or global parameters for updates, unicast, multicast, etc. What does take some time, is figuring out the global timers, especially if a person is not sure how they interact. In this post, we will address the RIP process level timers for update, invalid, hold down and flush. I don't want you to sleep during this, so we will save that one for later. Timers... Read More
Apr
08
One of our students in the INE RS bootcamp today, asked about an OSPF sham-link. I thought it would make a beneficial addition to our blog, and here it is.  Thanks for the request Christian! Reader's Digest version: MPLS networks aren't free. If a customers is using OSPF to peer between the CE and PE routers, and also has an OSPF CE to CE neighborship, the CE's will prefer the Intra-Area CE to CE routes (sometimes called the "backdoor" route in this situation), instead of using the Inter-Area... Read More
Apr
06
Having a blast in Chicago with the RS bootcamp students.    Thanks for all the hard work you are doing this week! A student from a past Reno class, named Michal, asked if I would create a blog post regarding BGP proportional load balancing based on the bandwidth of the links to EBGP peers. It has been on my list of things to do, and here it is. Thanks for the request Michal. The secret to this trick is to pay attention to the links between directly connected external BGP neighbors, (in this... Read More
Mar
28
Embedded RP, with IPv6 multicast, is a very cool trick. It simply embeds the RP IPv6 address as part of the multicast group address. This way, when a multicast router sees the group address, it can extract the RP and begin to use it for the shared tree immediately. The only thing that has to be hard coded on a router is to tell the RP that he is the RP, and that's it. All the other routers in the network dynamically learn the RP address from the group address. So here is the problem: A 128 bit... Read More
Mar
27
In a word, "Way to GO" (without the spaces, that would be one word :) ). I am impressed at all the feedback and ideas we received regarding the IKE phase 1 riddle we posed last week. You can read the original post here. Ideas were creative and varied. As one of our INE Instructors say, "If there are 2 different ways to configure something, as a CCIE candidate, you had better be prepared to know all 3 ".  If you would like to see "a solution", read on. Read More
Mar
25
Since IPv6 multicast doesn’t support the Auto-RP process like IPv4, there must be other methods for dynamically configuring a RP. The two options are using Bootstrap Router (BSR) and embedded RP. In this post, we will walk through BSR, step by step together. For BSR to work, we need to have at least 1 candidate BSR router, and 1 candidate RP. For fault tolerance, we would want to have at least 2 of each.   If a RP was on the network, but is powered down, I suppose that would make it a "Lost... Read More
Mar
24
IPv6 multicast routing is a fun topic, and is often either loved or avoided :). Here is a jump-start for all my CCIE candidate friends. Readers digest version: “Auto-RP is out, Dense-mode is out, IGMP is replaced with Multicast Listener Discovery (MLD). MLDv2 supports SSM. RPs, Bi-directional PIM, SSM, ASM and BSRs are still alive and well, and we can now avoid static RPs and BSR if we choose to use embedded RP within the multicast packets themselves. (Crazy and amazing stuff). Want a little... Read More

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