Multiple AS BGP Lab

I spent this evening creating one of the bigger labs I usually do. My task was to setup a BGP network with 5 AS's in which every AS should be able to reach other loop-free (requirement of BGP anyways). I was also supposed to make Router C choose Router A to send its packets destined for AS 65004. Well I was able to get the BGP network up without to many hitches which is a long way than just a week or two ago. I however could not get my route-map statement for Router A to set the local preference to AS 65004 higher than Router B to work. I'm not sure why but as i finish up this chapter i will review why this command didn't take. I think it might have been the way I applied it to the BGP router configuration (had the route-map set to in instead of out). All in all I would say it was a pretty good success setting up a lab of this size without having to really reference the book for command guidance.

Configure the Network Free Lab Book

Hey everyone, check out www.configurethenetwork.com to download your free ICND 1 lab book today!

BGP Peer Groups

I spent the better part of my morning learning how to configure BGP Peer Groups. Peer Groups provide a way to save router processing time by not having to send an individual update for each IBGP neighbor. If your Autonomous System has a rather large amount of routers (neighbors) running BGP, the processing time each router would have to run could be pretty intensive. Remember that when running IBGP within a transitive AS, all neighbors should be fully-meshed with one another due to the way BGP sends updates (unicast). I was also introduced to distribution lists and how they could be used to tune BGP updates. In the lab I created I used a distribution list to permit internal IP networks from being addressed outside the AS to other AS's.

As you see in the Router A BGP example, the commands to create a peer-group, distribution list, and creating updates for specific networks can be quite extensive compared to other routing protocols.

BGP Neighbor Configuration

After reviewing my CCNP study guide book this morning I finally ran into the material that would of helped me out tremendously yesterday. Sometimes I get a head of my self when studying because I will lab or study topics which hasn't been presented to me yet. This can be good or bad depending on how you look at the situation. What I came to find out when configuring BGP is that there's a huge difference between IGP and BGP network commands. When using the IGP network commands you are determining which interfaces should be apart of the IGP routing process. When using BGP network commands, you are determining which routes in the IP Routing Table should be apart of the BGP routing process. It's also important to note that the network you are referencing in the IP Routing Table will have to exactly match in your BGP network command.

For example if you have the route 192.168.1.0 /30 in your IP routing but type the following BGP network command:

network 192.168.1.0
or
network 192.168.1.0 mask 255.255.255.0

This will not work you will have to type the following:

network 192.168.1.0 mask 255.255.255.252

In order for BGP to include this route in the routing process.

Configure the Network Free Lab Book

To all of those who haven't signed up to the mailing list, I wanted to let you all know that the free lab eBook should be complete within the next two weeks! The people who are signed up to the mailing list will be the first to gain access to the download once it's complete. You can sign up on the right side of this blog, I try to send out a news letter weekly.


There will be two versions of the CtN Lab book. The free version will be based off of mostly ICND1 material. The full version will contain the following:

-Working Solutions for all labs

-More than twice the amount of labs offered in the free lab book

-Both ICND1 and ICND2 material (Entire CCNA Exam Blueprint)

And many more features to come! Pricing has not yet been determined for the full lab but I want to make sure that's it's more than affordable to everyone. If you have any questions please feel free to email me at: configthenet@hotmail.com

Configuring BGP

I spent most of my early afternoon configuring BGP for the first time. I was honestly a little nervous about if I was going to get this protocol up and running because I hear so many stories about how in-depth this particular protocol was. It actually took me a little while to get my lab up and working with this protocol because I wasn't sure if i needed to synchronize my BGP routes with my IGP (EIGRP) or not. I ended up using loopback interfaces as my update sources and configured my AS 65101 as a full-mesh BGP even though I' sure I didn't need to in retrospect since the AS wasn't a transitive AS.

Transitive AS's pass on BGP routes from one AS to another AS, in other words it's like a middle-man in the BGP routing process. I also had problems with my network statements, at first I didn't realize you even needed to use network statements since you were using the neighbor commands. Even after using network commands my BGP routes still wouldn't propagate to each other. After a little research i decided to define the specific subnets that I wanted to be used for routing updates. As soon as I did that all the routes came right up!

BGP Attributes

Today I studied the different BGP Attributes that are used to determine routes. There are Well-Known Attributes and then there are Optional Attributes. Well-Known attributes must be recognized and propagated to BGP neighbors. Optional Attributes may be propagated to neighbors depending on the attributes meaning. Within these two types of attributes, there are sub attributes.

Well-Known Mandatory Attributes (Must be included in BGP Updates):
- AS-path
- Next hop
- Origin

Well-Known Discretionary Attributes (Not mandatory to be included in BGP Updates):
- Local preference
- Atomic aggregate

Optional Transitive Attributes (Must be passed to other AS's even if attribute isn't used):
- Aggregator
- Community

Optional Nontransitive Attibutes: (Doesn't have to be passed to other AS's):
- Multiexit-discriminator (MED)

I've also reviewed how BGP Synchronization works along with the many BGP message types. Synchronization tells BGP to wait until all routers have the same IGP information before updating other AS's with the info when using redistribution of BGP into IGP. From what I've been reading synchronization is outdated as most BGP updates are to large to be redistributed into IGP's anyways (scalability). BGP message types are used for establishing BGP neighbors along with providing keep-alives and BGP router updates

BGP Path Vector Characteristics

I spent my morning learning about BGP and its path vector technology. Path Vector is like an updated scalable version of distance-vector routing. However it has one main difference than any other distance-vector or IGP. BGP doesn't use broadcasts or multicasting since it uses TCP as it's transport protocol. TCP is used because it's able to send a large amount of data reliably, the BGP table has over 190,000 entries in the full routing table currently! This size would actually be in the millions but thanks to technologies such as CIDR, the table size has been reduced considerably. Since BGP doesn't use any type of broadcasting mechanism, an AS being use to transit BGP routes between other AS's must be fully meshed within the transit AS. In other words every router running BGP in a transit AS must be seen by every other BGP router in that AS. this is becuase the BGP updates are sent as unicast messages which aren't forwarded in a multicast manner i.e. one-to-one mesages.

CCNA Configure the Network free lab book is on the way soon! I should be completed with all of the labs for this eBook by sometime next week. I will also need my work to be edited for the final version as well. If you haven't already please subscribe to the mailing list on the right to be the first to receive updates and a link to download the free CtN CCNA lab book!

CCNP BGP Overview

Well today I finally started the chapter for BGP, I've been waiting to get to this one for a while. I went over the first section of this chapter which gave me a brief overview of what BGP is. I can already tell that there is a lot to this protocol looking at the number of RFC's alone! The fact that this is the biggest chapter in the book (over 100 pages) is another reason. I ended my study session by viewing a few multihoming options an AS has when receiving EBGP updates from multiple ISP connections.

Don't forget to sign up on my mailing list to the right to be the first to receive my free CCNA lab book! The book is only a few weeks away to being completed!

Chapter 7 BSCI Configuration Labs

Today I finished up the end of chapter configuration labs which helped me wrap my head around all of the topics presented. Everything went fairly smooth but I will need to review the commands and variables for distribute lists, route-maps, and dhcp settings. These 3 commands gives the engineer a ton of flexibility in tuning routes for a network.

In other news, I am a little more than half way finished with the free lab book I'm creating and I plan to be finished in about 2 weeks. If any one is interested on being notified when the final product is finished, please subscribe to my mailing list on the right!

Progress on the first "Configure the Network" eBook

Thanks to all the people who replied and all of the positive responses so far for the CCNA Lab book. If you're interested in receiving a copy please sign up on the right with the mailing list I just created! I'm using this as a way to keep things organized as a ton of emails have flooded in and i don't want to mistakenly leave any one left out. as mentioned I am breaking this CCNA lab book into two parts for the ICND1 and ICND2 respectively. Below you'll see the rough draft of the outline I have created for the ICND1 labs. I'll also keep you updated via the mailing list so stay tuned!


I. Introduction

1. Configure the Network

2. Contoso Technologies

II. Contoso Task 1

1. Configure Client’s Cisco Switch

III. Contoso Task 2

1. Design and Configure Client’s SOHO Switch Network

2. Implement and Verify Switch Security Measures

IV. Contoso Task 3

1. Configure Client’s Cisco Router

V. Contoso Task 4

1. Configure Small Business Client’s LAN Network

2. Create DHCP Solution for LAN Network

3. Implement Solution to Access Remote Building’s Network

VI. Contoso Task 5

1. Develop LAN Network for College Campus Buildings

2. Provide Access to other Campus Buildings Using RIP

VII. Contoso Task 6

1. Configure Client’s T1 WAN Link

2. Change WAN Link for Multi-Vendor Use

3. Install Multi-Point Connection for Redundancy

VIII. Contoso Task 7

1. Build Cisco Inter-Network for Medium Business Client

Feel free to leave comments on what you would like to see on this lab!

Tuning Route Redistribution using AD

Today I went through a quick study session and lab that shows how administrative distance can cause suboptimal routing when using route redistribution. I tested this with a lab that was redistributing RIP and OSPF both ways. Since OSPF has the default AD of 110 and RIP has an AD of 120, the ASBR routers redistributing chose the OSPF routes even when the RIP routes were closer. To modify this I had to create an access-list with all the possible RIP routes and assign it the AD of 125 on the two ASBR routers and inject the access-list into the OSPF routes. Now when the ASBR's received a RIP route from OSPF (due to redistribution) it automatically had an AD value of 125 which was larger than the default RIP AD 120. The RIP routes were installed into the ASBR's routing table due to having a lower AD value of 120!

Route Maps and Distribution Lists

I spent most of my afternoon covering the topics for Route Maps and Distribution Lists. I've actually been waiting to get to this topic for quite awhile because I see these commands in my work environment all the time. Both of these tools are similar to access-lists but their purpose is to tune or route specific IP packets. Distribution lists filter routing updates which is something you can't do with a regular access-list. Route maps gives the engineer a lot of flexibility on what specific ip packets should be tuned and what should be tuned such as the router metric. Tomorrow I will learn more about tuning administrative distance (AD) to control the flow of routing packets.

Controlling Routing Updates

This morning I spent most of my time learning about passive-interfaces and the many ways we can control and tune routing updates. This chapter actually puts together a lot of pieces to the puzzle because it explains how routing protocols work together and how you can limit what each protocol knows about the other specifically. I also learned a little bit about distribution lists and will be creating a few labs for this tomorrow.

In other news I'm creating a lab ebook for all of you CCNA test takers out there so be on the look out for that. I will most likely make it a series along with splitting the ebooks up into ICND1 and ICND2. I want to make sure that the series is not only helpful but also very affordable because we all know that the study material, equipment, and exam isn't cheap by any means. I'm actually looking to hand out a few beta copies of my book for free to review and provide constructive criticism. Email me at shawnmoore_1@hotmail.com if you're interested and I'll add you to my current list of reviewers, spots are already filling up so be hasty!

Redistributing between Routing protocols

Today I spent most of my time going through the various redistributing differences between routing protocols. The hardest redistributing to remember was the metric for the protocols that used distance-vector technology which is RIP, EIGRP, and IGRP. The metric for these protocols have a default value of infinity which means that any other routing protocol wouldn't be redistributed unless you defined the metric that is to be used. Also OSPF doesn't redistribute classless IP routes by default, you have to specify that subnets will be used for whatever reason. IS-IS was surprisingly the easiest but maybe that's because I just finished that chapter last week? I have a ways to go to finish this chapter won't be until sometime next week most likely. I will run through some labs in my portable command-guide the next few nights to get some more practice with the theory I've learned so far.

Chpt. 7 Redistribution Overview

Today I went over the beginning pages of Chapter 7 regarding manipulating routing updates. This chapter started off with route redistribution which I have a little experience with all ready from previous labs and on the job experience. The pages I read went to the reasons why you would want to redistribute and situations that you want to look out for when injecting different AS protocols into another AS protocols. There really wasn't much to lab but I did create a lab based on an example provided in the study-guide book. Tomorrow should be a lot of configuration using the various routing protocols that has been learned through out the book so far.

Chapter IS-IS End of Chapter Lab

Today I finished up the short Chapter 6 lab on IS-IS and actually managed to get everything up and working this time. I'm still not sure why my other IS-IS lab wouldn't inject the routes correctly as I should so I'll probably run over that labs configuration again at some point. I also ended the chapter by finishing the multiple choice questions presented. As current CCNP's and above mentioned, the questions presented in the back of the book are CCNA level type of questions which really doesn't help enforce your command of the topics given.

I'm actually only 4 chapters away before finishing the entire book so I'm making really good progress thanks to the holidays I was able to get some extra study time in at work. Once i finish the study guide and go through the portable command-guide book I'm going to purchase the exam and lab guide and double up my studies. Once that's complete I'm going to hopefully fill in any gaps by going through any labs and CBT's from Cisco.com I can get my hands on along with going through white papers and RFC's. Repetition Repetition Repetition is the key to mastering and becoming successful with anything I believe, hopefully it pays off for the exam!

IS-IS Configuration

Well i finally came across a lab for IS-IS, this is going to be a topic I'm going to have to come back and review a little harder for sure. The most confusing part about configuring IS-IS is remembering that a IS can only be in one area unlike OSPF but the interfaces on the IS can be set to send specific IIH PDU's (L1, L2, or both). There isn't an ABR like OSPF that sits in between two areas, also IS-IS doesn't use an area 0 bypassing hierarchy which allows for better scalability with IS-IS. I had some problems getting my loopback interfaces to connect via IS-IS even after redistributing my connected links into IS-IS I had problems. Tomorrow there's the end of chapter lab so hope fully i can better get my head wrapped around it! I also tested some SSH connections by setting up static host mappings using the ip host hostname ipaddress subnetmask command. I created loop back interfaces for my host ip address which as we know never shuts down compared to using a real serial or Ethernet interface. I want to start some security but I know my time will better spent focusing on the core CCNP topics. I'm going to have focus on all the topics presented thoroughly in order to pass the BSCI.