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Showing posts from 2007

CCIE BGP ORF

This days I am a little slow on article writing as I am in the final lap before my lab exam (wish to pass..) ok that was on a personal note. Now on a hopefully helping note, i had a little bit difficulty understanding first the logic behind ORF but when the coin dropped then I started hearing a voice in my head saying tada... So here it how it goes, the real BGP full table is currently almost 250K path entries, now you have connection to 3 ISP's and you want for example to get from your Backbone ISP the full table and from your other ISP's only partial table, you then face with a dilemma should I develop my human bagging skills to ask nicely from each ISP's to filter on his side specifically for you and what you will probably get as answer is "NO" or if he is nice then "NO". So now you face with a problem you can get from each of the ISP's the full table and filter on your side but it will not solve the performance and resource intensive problem …

Mary Christmas and Happy New Year

To all of you that study during the holidays and thinking they are the only one, well you are not alone. Our dedication to the goal is what Differentiate us, an expert is not the one that know all, it is the one that is most dedicated to find the best solution and do what ever it takes. So Mary Christmas and Happy New Year to all of you out there :-) Now let ABBA Continue from here....

CCIE EIGRP METRIC

One of the annoying fileds in my opinion is calculation, I hate them! in my mind it is just in the way of the cool stuff. but unfurtunetly to get to the cool stuf you need to calculate.

so I would like to start by giving you a little review and may be more indepth look over EIGRP Metric, as we all should know EIGRP is a Hybrid Routing Protocol that use a Composite Metric in his DUAL Diffusing Update Algorithm. the Composite metric is composed (good word selection :-)!?) from K Values.

K1 K2 K3 K4 K5

K1 = Bandwidth = 1 meaning it is used in the calculation by default.

K2 = load = 0 you gust it, meaning that is not participating in the calculation by default.

K3 = Delay = 1 you can take it from here

K4 = Reliability = 0

K5 = MTU = 0

the K values tells us if the value is participating in the calculation or not and what is the weight of the value, meaning that if you set K1 to 3 then it means that the weight of K1 will be 3 times more "important" or in other words it will take the BW * …

IPV6 Tricks

Have you ever faced with a situation where you where stuck out of your server due to a IP Address Change, well if you didn't you might one day, let me tell you how IPv6 Saved me. I have several Linux Servers in My Company and Due to some maintenance I needed to change the IP Address on on of them, simple task although it went bad due to a miss spelling on the ifcfg-eth0 file. and like I love to go fast with configuration I did a stupid mistake and restarted the network service well needless to say that as soon as I did that I was left outside, started yelling and spelling out some wired brrrrrrrhmmmmgrrrrrrr and all sort of mad words. but then I said to my self hey i am an almost Expert I know Networking, how do I solve this, well the port is still listening on the Ethernet Network so If I had some way of login via ARP or MAC or Other Protocol then I was good to go, and then it pupped out to me IPv6 use in link local address based on MAC address and I have the MAC address of my …

CCIE IP Precedence Vs DSCP Values

The Table bellow Represent the TOS filed in the IP HeaderIPP IPP IPP DropP DropP 0 ECN ECN Drop P = Drop Precedence IPP = IP Precedence The Drop Precedence means the probability that the packet will be dropped, the higher the value it is more likely to be dropped. IP Precedence is the importance value of a packet, the higher the value the packet is more valuable. In IP Precedence we have 0 – 7 values and you can see that by looking into the amount of fields that we have Routing (Best Effort) - 000 Priority - 001 Immediate - 010 Flash – 011 => mainly used for Voice Signaling or for Video Flash-Override - 100 Critical – 101 => mainly used for Voice RTP Internet - 110 Network - 111 You do not need to remember the name value of each one, you can simply see it with: TermServ(config)#access-list 100 permit ip any any precedence ?(0-7) Precedence valuecritical Match packets with critical precedence (5)flash Match packets with flash precedence (3)flash-override Match packets with …

CCIE INTERNETWROKEXPERT

I would like to express my grate appreciation to the contribution that Internetworkexpert brings to the Technical Community, although they are a commercial company they do give away free seminars and do help people that are in need to learn and do not have a lot of financial resources to do that.So Thank you InternetworkExpertHere is a recent v-sminar that was added on IPv6 http://classroom.internetworkexpert.com/p23982603/Soon they will release a v-seminar that was transferred yesterday for free on Catalyst QoS.Also grate thanks to there top notch instructors:Brian Dennis, CCIE #2210 (R&S/ISP Dial/Security/Service Provider)Brian McGahan, CCIE #8593 (R&S/Service Provider/Security)THANK YOU!

CCIE SecureCRT Tip

As you all know the mostly used terminal in the CCIE lab exam is the old SecureCRT from http://www.vandyke.com/ without the tabs addition. but what you do have is the key mapping.you can set for example:F6 to be the CTRL SHIFT 6+x by simply setting the send sting in the key map to \036xF7 to be CTRL SHIFT 66 sequence of braking in the middle of a trace or a ping when you connected with the Access Server by mapping \0366 I my self practicing without the shortcuts but each person with its own methods and tactics. I believe the quest is like a preparation for theOlympics so practice practice practice.

CCIE VERIFY RPF FAIL

One of the major issues with Multicast is finding the RPF and making sure that there is no Failure in it, as if we do have a fail we can patch it by adding ip mroute (like a static route but only to pass the RPF, not actually changing the path of the packet). So how we can find such fail we have several tools the first one is to find if we have rp mapping. R6#sh ip pim rp ma PIM Group-to-RP Mappings Group(s) 224.0.0.0/4 RP 150.1.5.5 (?), v2v1 Info source: 150.1.3.3 (?), elected via Auto-RP Uptime: 00:14:48, expires: 00:00:02 R6# we see here in that example that we do have RP Mapping so we defiantly passed the RPF. I have made an RPF fail and we now will try to trace it: R6#sh ip mroute count IP Multicast Statistics 3 routes using 1962 bytes of memory 3 groups, 0.00 average sources per group Forwarding Counts: Pkt Count/Pkts(neg(-) = Drops) per second/Avg Pkt Size/Kilobits per second Other counts: Total/RPF failed/Other drops(OIF-null, rate-limit etc) Group: 227.0.0.1, Source co…

CCIE PIM AUTO RP

In that section I would like to talk about Auto-RP, well not until recently I have had little to say about multicasting as it was something I know but like most I didn’t really understand or have struggled to really see how it works, I only know that when you enable it, you basically save bandwidth by using one stream instead of unicasting to each and every station, and on the basic it is true but the how it works is more important for us candidates. So here I will show you how the Auto-RP works and what tools do we have to make it work. Well we should all know that we have today 3 basic operation modes of PIM Sparse Mode – or as it called source tree and it is mostly used today Multicast Networks using a Pull Technology meaning if you do not ask I will not send it Dense Mode – or as it called shared tree and this is the very basic of Multicast using Push Technology meaning I will always send and if you say you do not need it I will Prune back but after a certain time out I will ag…

Web Design

Hi Guys, I know it is not related to the main subject of my blog but I would like to give here a Little credit to my brother and his partner new Web Design business.I think you should to EG STUDIO

CCIE Regular Expression in BGP

I think one of the most scary configuration is when using Regular Expression (at least for me)it took me a while and I am still straggling from time to time, although I am writing to you about this I am sorry to say there is no easy way to get it. you just need to put it in your headI believe the each explanation has its own advantage as some people understand reading manual some need a trainer to lecture them.Here I will give some of my own explanation to the common regular expression:* all char, mean when you use this it can be any char ^ start here, for example ^5 mean any thing that start with 5 so it could be 5 or 500 or 54 or 5000000$ end here, for example 5$ mean any string that end with 5 so it could be 455 or 45 or 5 or 3005_ (underscore) start or end or space, this is a nice one as it mean you can either start a string or end a string or simple space. example _5_ can only mean 5 but _5 can mean 5 or 500 or 54 or 5000000 and 5_ can mean 455 or 45 or 5 or 3005[] brackets, I do…

CCIE QinQ

I must say this is one of the technology's I love and some times also love to hate as it can make you very confused on where to start and what to do to make it work, but once you do make it work you fill like Houdini.

why like Houdini because basically the technology make your middle switch go away like it never was there and sowing to the person you wanted to show like he is directly connected to a switch when he is not.

now that I made every one a little confused, i will start to explain, QinQ allow you to take a middle switch and turn it to transparent while connecting 2 other components and maid them fill like they are directly connected.





why do you need that, well the CCIE lab love it as it is confusing setup but there are more reason then that, with QinQ you can connect topology's while you migrating, you can also connect between clients that have there own topology that you do not want to encounter in your topology by transferring all of them with a single tag between ther…

CCIE LAB with Dynamips

I am proude to present to you my first LAB design with Dynamips, it is a 5 router topology with the use of FRSW and ETHSW from Dynamips.

I am working today with IEWBv4 to get my number. during my study I have said to my self why not create also your own LAB topology with your own scenarios, and here we are.


you can download my .net and initial config


As for the Lab Scenarios rules:

1) Do NOT use Frame-Relay Inverse Arp
2) Do NOT use sub interface with int Frame-Relay
3) There should be connectivity trough out the network include routes advertised from BB1
4) Y represent the Router number

General
1) Set loopback interfaces on R1/R2/R3/R4 with 150.1.y.y

WAN

1) Set Connectivity on the Frame Relay cloud between R1 R2 and R3
2) set Connectivity on the Frame Relay cloud between R4 to BB1
3) Set Serial using ppp between R3 and R4
4) I am a little afraid from unwanted users so please make sure you add on MD5 authentication between R3 to R4 and to make it more efficient as most of my traffic is txt files …

CCIE PPP over Frame-Relay

first I would like to start by explaining why we need it and how it is going to take our simple frame-relay to another level of connection, as we all know Frame-Relay is Layer 2 Technology design to reduce wide band use by sharing connections and grunting or not grunting link speed, today as you probably know the frame-relay has become obsolete by other technology's such like ADSL, Cable, Metro Ethernet and others.

ppp (point to point protocol) another layer 2 protocol design to give a better solution to hdlc (high level data link control) used to control and transport ip traffic in a reliable and secure way.


now people taught how do we give the old frame-relay more features without developing a new frame-relay, they said why not take the good old ppp and join them in a "holy matrimony" just kidding, but really why not take them both and enjoy both benefits one with sharing bandwidth and traffic shaping options and one with link integrity and security features.


so now I com…

Warrning !!!

This is not related to the context of my blog but I would like to put here a warring against this E-Bay Seller, he sold me and others a fake Nokia N95 Model and you can see in that movie what a rip off it is! here is the link of what he sold on eBay and on the movie you can see what I received: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=160123539029&sspagename=ADME:L:RTQ:US:1 So Be Ware

MPLS BENEFITS

1) faster switching then IP as IP Forwarding is based on IP routing table search each address is 4 octets length and can cause some time to calculate 2) Core free from BGP as the MPLS is based on label switching there is no need any more for core routers to participate in the BGP network and only Edge routers need to be BGP aware. this is a huge memory and utilization saving. 3) MPLS TE Traffic Engineering is one of the major benefits as it is allowing you to have better path selections and it have a very good mechanism called FRR Fast ReRouting and this is allowing to re-route traffic from and unavailable router in a really fast speed of less then 50ms, and this is allowing us to build a stable and reliable Data and VoIP Network as you know less then 50ms loss will still keep the Voice Call Up, if it is more then that the call will be dropped. so this feature allows us in a good planed network to give us near PSTN solution. 4) MPLS VPN is another major benefit as it is reducing manag…

CCIE OSPF Behaviors

There are five main behaviors when working with OSPF, some people get confused between them and I my self had a painful time understanding at the beginning what the hell we need them and what difference dose it make using one or the other.Broadcast - for shared network environment like Ethernet as you can see bellow by tweaking the interface behavior you can adjust also the timers and make it send multicats instead of unicast: Router1(config-if)#ip address 1.1.1.2 255.255.255.0Router1(config-if)#ip ospf network broadcastRouter1(config-if)#endRouter1# show ip ospf interface s0 Serial2 is up, line protocol is up Internet Address 1.1.1.2/24, Area 0 Process ID 1, Router ID 3.3.3.3, Network Type BROADCAST, Cost: 64 Transmit Delay is 1 sec, State DR, Priority 1 Designated Router (ID) 3.3.3.3, Interface address 1.1.1.2 Backup Designated router (ID) 2.2.2.2, Interface address 1.1.1.1 Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit …