Wednesday, March 28, 2007
As I have encountered lately with numerous questions regarding Routing Protocols using multicast I have some reminder notes: 1 ) Multicast is a destination Address, mean you will never see it in the SA of a Packet. 2) Routing Protocols Such as RIPv2 , OSPF , EIGRP use multicast by default although you can set them to other then the neture behavior 3) RIPv2 126.96.36.199 / OSPF 188.8.131.52 (All OSPF Router) 184.108.40.206 (All DR/BDR) EIGRP 220.127.116.11 4) Address range 18.104.22.168 - 22.214.171.124 are non routeable address, and you ask your self how can a routing protocol use a non routable address or what is non routeable address A) non-routeable address is when a packet is living one router and reaching his nexthop router the next hop will not send it further but he will recreate another packet if he need to update others B) So when we understand what is non-routeable address we hopefully understand why a routing protocol do not need a routeable address, as you send an update you know only your next hope (or as i call it your continues address) and you cant know what is beoned that unless you get an update on that. C) what brings us to another important rule the router that get the update never send back the same update trough the same interface he received it, and this is as you know preventing routing loops or as we call it "SPLIT HORIZON" 5) also regarding continues networks in addition to all the above if you want to form a neighbor relation with another router, in addition to the specific rules of each protocol, you must be either connected directly (same subnet) or make the router think you are directly connected (by using a tunnel interface). and why you ask because of the simple fact that if I don't know how to get to you in the first place how can i make a neighbor relation as you know we are talking about IGP internal routing protocols and not BGP that you can use the multi hop (but that's for another article). I hope this has been some interesting and helpful information.
Tuesday, March 27, 2007
OK guys first I would like to thank you on the feedback it is much appreciated that some one takes the time to respond to you on your time and effort. So I would like to add another .net topology that is smaller but very useful for IP Services practice like Proxy Arp, NAT, HSRP and all the things you want to test that do not require a full lab of 13 routers. the lab was prepared from the IEWBv4 IPServices book under Advanced Technologies also to people that do not have this Work Book it can be very handy as it is not very hard to figure the structure of the lab. And work you way trough all kind of scenarios. So Here
At first glance you say who have the patients to go trough this Doc Site but patients pay sometime and the site is one of the helpful when you have something to remember and you need a quick Guido. I my self have a method that I hope will also help you: 1) First you need to find out what you are looking for and this is buy understanding the question 2) Now when you know what you are looking for (example: BGP outbound and inbound influence) you open the DOC site 3) First I would look for under Cisco IOS Software and usually I will go to 12.4 4) then I will go to Configuration Guides where there is 2 12.4 and 12.4T 5) I would choose T if we are talking on special features, mostly I will go to 12.4 Configuration Guide 6) and then Select Routing Protocols and BGP and in BGP I will select Connecting to Service Providers and there you go to Configuration Examples and here in under a min you have a quick reference that can remind you how to influence BGP. Note: you now probably say what the hell is he talking about and what if it is something else I need to find, well the answer is understanding, you must remember that you cant go to the test find a new subject and start search for it on the Doc CD, it doesn't work that way. You MUST get the complete understanding on the technology and then searching for it is easy. I am going mainly to IOS 12.4 or 12.2 if it is something older (12.3 I find unhelpful) and if it is related to 3550 or 3560 Cat then I go directly to Catalyst Switches Section and to 3560 12.2(25)SEE and again to software configuration guide.
Sunday, March 18, 2007
Well for thous of you that are reading this the first time I have passed my CCIE Written (score 87%) and I am on my journey to become a Full CCIE. When I started my studies I have began with lots of reading almost every book I could lay my hands on. but there was basically a main book and from others I have expanded my knowledge so my main book was Cisco Press CCIE (Exam 350-001) Routing and Switching Official Exam Certification Guide by Wendell Odom, CCIE No. 1624 and in addition to that I have also rented several hours ~50 for practicing hand on lab and also I have taken both BOSON and TESTKING practice tests and I want to compare both for you
Scale 1 - 10 (1 lowest and 10 the highest)___________________BOSON__ TEST KING Questions Level _________4_________ 9__ Number of Questions_____9__________7__ Practice Exam Price______8__________6__ Simulator look and Feel___8__________7__ My recommendation is TetsKing in my opinion it is much better then Boson but need to be improved on the simulator functionality.
Tuesday, March 13, 2007
Monday, March 12, 2007
As you probably know already the Switching part in the lab exam is now taking a grater part in the lab score ~20 points so it is definitely a major subject. VTP (VLAN Trunk Protocol) key points for the lab: In the lab you will have 2x3550 and 2x3560 making configuration of VLAN and VTP slight more interesting and very interesting for spanning tree but this is for another post. vtp default mode is server on server mode you can create modify delete vlan assign password for higher security. vtp check revision numbers the switch with the higher revision number win and update all. mean that if you insert into a new setup a switch that was in production or was handled to show a higher revision number will mess up all your setup so it is most recommended to delete flash:vlan.dat ! all the vlans info is kept in that file ! set / check the vtp mode to server vtp mode server ! set a new vtp domain vtp domain newCCIE ! set a password other then cisco notice that the password is case sensitive vtp password otherthencisco ! and only then install it into your topology !for the lab i would check the vtp status show vtp st ! if status or revision or configuration of vlan is not suitable to my needs ! i would change the domain name to a different domain and re change it to the needed ! domain this would make the revision number to 0 Version of the vtp is not so much concern unless specifically asked as the difference mainly between ver 1 to 2 is the support of token ring on ver 2 VTP pruning is a nice feature that allow the switches to save some traffic by pruning unnecessary vlan traffic. vtp modes : Server as was mentioned before this mode is to allow to create modify and delete vlan Client is not allowed to create delete or modify vlan information Transparent is allowed to create modify delete vlan only on the local switch. VTP is used to transfer multiple vlan information and due to that it can only travel between trunks, so if you have problem with vtp information propagation check your trunk, also one of the switches must be server and other clients for the information to be transferred properly. also ver1 and v2 are not compatible so make sure all switches use the same vtp version. Another key difference between ver 1 and 2 In Transparent mode vtp advertisement that travel trough the switch are drop if not on the same domain, but on ver 2 it is propagated and not dropped. Hope this was some informative review on vtp, note that there is much more to vtp then what I have specified here but I think I have summarized some key features that I use in my practice and real life.
Bgp (Border Gateway Protocol) is one of the major topics in the exam and from my point of view the most complex one, as there are so many things that can be achieved with configuring BGP due to the flexibility of the protocol. In my quest of learning I also go trough documentation outside Cisco as it is important to get to know the protocol as it is and not only the Cisco point of view. So I came across with this fine PDF i am sure you will love it if you didn't already know about it before, it is a small reminder on the basics of BGP. "Nice to see the number of bgp entries is almost 300000 this is an amazing jump in entries from 2001 also you have there some other interesting reports only for general knowledge"
Tuesday, March 06, 2007
I have done some work for my self and I would like to share it with you, I want to point out that there is no real substitude to the real deal but the Dyanmips is the closest thing and it helps a lot with your practice as not every one can afford a full lab equipment or even lab rental some time can add up to a substantial amount of money (i have spent until now ~600 - 700USD on rent time) so for sure the Dyanmips is saving a lot. I have modified the IEWBv4 of internetworkexpert for you to be able to just load each time the lab you want and start work instead of waisting time on configuring IP's and init config also as you know some of the init config are also the task to find what is wrong with init conf. So you can Donwload it from Here also do not forget to create a Bash file for opening ports #!/bin/sh nice /home/dynagen/dynamips-0.2.6-RC5-x86.bin -H 7200 & nice /home/dynagen/dynamips-0.2.6-RC5-x86.bin -H 7201 & nice /home/dynagen/dynamips-0.2.6-RC5-x86.bin -H 7202 & nice /home/dynagen/dynamips-0.2.6-RC5-x86.bin -H 7203 & nice /home/dynagen/dynamips-0.2.6-RC5-x86.bin -H 7204 & nice /home/dynagen/dynamips-0.2.6-RC5-x86.bin -H 7205 & nice /home/dynagen/dynamips-0.2.6-RC5-x86.bin -H 7206 & nice /home/dynagen/dynamips-0.2.6-RC5-x86.bin -H 7207 & nice /home/dynagen/dynamips-0.2.6-RC5-x86.bin -H 7208 & nice /home/dynagen/dynamips-0.2.6-RC5-x86.bin -H 7209 & NOTE: All the config is optimized for Linux (my choice of OS as the performance is better)