Welcome, It is 2:24 AM on a Tuesday morning and I'm here at work not doing much. Yea I am slacking off a little... So what comes to mind at this time? The new lab I just bought!!! Yes, I sold my old one and bought a better one. I now have 4 2811 Cisco routers, and 3 3750 switches and I also upgraded the modules to 16FE interfaces so I can do some heavy bundling between the routers and switches. This will be my CCIE lab and I am planning to maybe get 1 more switch but that will be later. I am also considering getting a full blown Juniper lab as well, so soon I am going to have 2 decent lab kits from 2 different vendors to get them to work together. Juniper and Cisco, to me, provide the best equipment and certifications in this market and both have a very high demand. With that being said, I wanted to talk about my CCNA experience. I honestly didn't know much about networking. I had some knowledge but definitely not on a CCNA or CCNP level. The real reason that interested me was because it was available for self studies and it was cheap. I never thought the potential that it had until I really got involved. I had bought a decent lab 4 2600 routers and 4 2950 switches. But do you really need 8 devices you might ask? The answer is no. You can definitely have a decent lab by just having 2 routers and 2 switches both the 2600 and 2950 models if money is tight. A website that is good to buy CAT5 cables straight and crossovers is in Monoprice.com. They have very cheap cabling if you dont have the tools to make them. So the equipment was in an ok condition when I bought them but after a while they started failing, which to me was great. I learned to replaced the fans, modules, RAM memory, Flash card, and even the serial cables and interfaces which I had to change the clock rates to get it to work. I also learned how to set it up with my cable modem as the gateway. Everyday I studied for a few hours and on the weekend it was time to hit the lab. The downfall was how loud those routers are and how much power it eats up so beware! I also used Microsoft One Note to take notes. You can take that free app anywhere including your phone and have nice and clean organized notes. You MUST take A LOT of notes when studying this, trust me it can be hard to remember all these protocols. Anyways I wanted to share a subnetting trick that I had posted on my IG account. Once you master that chart, subnetting will come in easy and that will be the least of your worries while taking the test. Remember time will NOT be in your favor while taking the test so you have to really check your time and not spend so much time in one question. I actually failed my first test, the ICND1. I was soooo mad and I hated Cisco for it, but after my second attempt, I passed it fine. So here it is and hopefully you enjoy it....ATTACKING A SUBNET Many students nowadays have questions and difficulty understanding what subnetting is. I have made an easy explanation on how to solve subnetting questions to ace the test and to use it in the real world. I will be honest, more than likely you will not subnet a network by memory when you get hired for a networking job. The entire network is already designed. Calculators and programs have been made to ease the pain. But, the purpose of this tactic is for you to attack it on the day you won’t have a calculator in hand, like your test day. Hey maybe you forgot how to subnet because you have been so used to using a calculator like me. Before you continue, you must have some understanding of what subnet masks are and their purposes. If you don’t, then you must go back and hit the books. First thing is first, having a visual chart will help you tremendously when subnetting a network. So let’s first start with this chart. When the day comes that you have to take your CCNA test, I would HIGHLY recommend writing out this simple chart quickly before the test starts. The test does not have enough time for you to spare. 128 64 32 16 8 4 2 1 192 224 240 248 252 254 255 So what do you do when you have 192.168.1.0 /25 mask? Well you must know that a subnet mask is composed by 8 bits for every decimal. 255.255.255.255 = 8bits.8bits.8bits.8bits = 32bits So what happens when you have a /25 mask? You just add the first 3 decimals equal to 24 bits. Then you only have 1 left right? 255.255.255.? = 255.255.255. (Add the first one from the graph horizontally which is 128) 255.255.255.128 is your subnet mask What about a /26 mask? 255.255.255.? = 255.255.255. (Add 2 from the graph horizontally which is 128 + 64 = 192) 128 64 32 16 8 4 2 1 192 224 240 248 252 254 255 One more example, what about a /27 mask? = 255.255.255. (Add 3 from the graph horizontally 128+64+32= 224) 128 64 32 16 8 4 2 1 192 224 240 248 252 254 255 As you can see, your answers are already in the graph. You just need to add the same amount of bits that you used horizontally to vertically. Now, what do you do when you have the subnet mask? You subtract 256 from whatever you have left on the subnet mask. Using a 192.168.1.0 /25 mask, you subtract 256 from 128 and that leaves you with a 128 subnet block. This means that you only have 2 subnets to use. Remember to subtract 2 for the subnet ip address and broadcast ip address. EASY RIGHT?!!!! 256-128 = 128 subnet block 192.168.1.0 ß 192.168.1.128 192.168.1.256 SUBNET IP MASK 192.168.1.0 255.255.255.128 USABLE IP ADDRESSES BROADCAST IP 192.168.1.1 to 192.168.1.126 192.168.1.127 After attacking this /25 subnet, now you know that you can have 2 subnets and 126 hosts in your network. Ok one more that is not a common one. What is the subnet mask and usable IP addresses for 18.104.22.168 /28? = We already know the first 3 decimals are 24 bits. Add 4 bits to make it 28. 128 64 32 16 8 4 2 1 192 224 240 248 252 254 255 256-240= 16 subnet block 22.214.171.124 126.96.36.199 ß 188.8.131.52 Subnet IP 184.108.40.206 Mask 255.255.255.240 Usable IP Broadcast IP 220.127.116.11 to 18.104.22.168 22.214.171.124
Welcome, Today's blog will be about HFC (Hybrid Fiber Coax). I have 6 years of experience in HFC troubleshooting and installation and one thing I can say is that it is very interesting! HFC is the combination of a Fiber and Coax network that some ISPs like Time Warner, Comcast, Charter, Cox, etc use. It is very interesting because it has a lot of different types of equipment used to provide TV, Internet, and Voice services. The way it is designed is by having most of the networking and transport equipment at a local Headend. It is like the "brains" of the network. There it will receive TV content via satellite dishes or via IP streaming. The networking routers and CMTS would be located there to provide the WAN internet connection and the PSTNs would be there for the voice services. The modulators and demodulators are there to encode TV RF (Radio Frequency) signal throughout the entire HFC network. From the Headend, it will travel and connect to a Node via fiber cables. The node is located in the field to convert it from fiber to coax, hence the word HFC, and the coax trunk cables that are running across the poles or underground go through amplifiers to amplify the signal until it reaches a tap. The tap is the connection at the pole or at an underground pedestal by your home. Remember back when people would steal cable and they had a guy do it for them on the side? Well they would connect the RG6 cable to the tap where it grabs the RF signal. Once the cable reaches the inside of your home, the signal would be split through a device called a RF Splitter and the cable would connect directly to your cable modem or cable box. The biggest issue with cable is weather. The heat, cold, cracks, kinks, bends, or connector suck-outs would cause intermittent internet issues and tiling on your TV signal. My best advice is always make sure your coax cabling is no more than 6 years old. It can definitely last longer but if you move in to a home older than 6 years, its better to replace it and be sure your wiring is up to date. Also, the best cable to use for the inside of your home is RG6! Always replace RG59 cabling. That type of cable is very old and definitely not strong enough to carry the amount of RF signal and bandwidth nowadays. Today I wanted to post something different. I wanted to take a break from networking because it can get frustrating sometimes when you are studying a lot, but next blog I will come back to talk about another routing protocol whether its EIGRP or BGP. I still haven't had someone request an explanation for a particular topic or routing protocols so I will just post whatever comes to mind. You guys can always ask me anything even lab examples! I enjoy doing this. Anyways, I hope you learned something today and if you have any questions let me know! Here is a really good and simple picture that Wikipedia posted regarding HFC.
In celebration of World Asteroid Day this week, scientists came out of the woodwork to explain to all the different ways we can prevent an asteroid from causing an Armageddon-level apocalypse.The European Space Agency used the occasion to promote its proposed Asteroid Impact Mission, which would study how an asteroid’s trajectory could be altered using a so-called kinetic impactor. They also released this series of images, which show us how missions designed to stop a space rock from slamming into our planet and annihilating all life on Earth—while clearly heroic—might also be quite beautiful.While the chance of a kilometer-scale asteroid slamming into the Earth and eviscerating our biosphere is quite low, even a relatively small space rock could cause serious damage. What’s more, developing asteroid redirection technology for defense purposes may pay off in unexpected ways. If, for instance, we can use kinetic impactors to nudge a platinum-rich asteroid our way, well, that’d pay for the cost of the mission a thousand times over.source
What Makes a Watch Smart?While there is no standard definition of the term "smartphone" across the industry How can we define a "smartwatch"?as i know smartwatch provide features like connecting to the internet, running mobile apps, making calls, messaging via text or video, checking caller ID, accessing stock and weather updates, providing fitness monitoring capabilities, offering GPS coordinates and location directions, and more.A number of companies either currently have smart watches on the market or are rumored to be developing smartwatches, including Google, Samsung, Apple (the "iWatch"), Sony and various others.
Running into the adware program known as Qone8 is an unpleasant experience, to put it mildly. To begin with, it completely disregards such things as user authorization when entering a computer system. Also, the pest needs no permission to change web browser settings that are conventionally supposed to be at the user’s discretion. Overall, it acts as though all of these privileges were granted to it by default, whereas they are definitely not. The things affected by Qone8 as it intrudes on a PC include the browser homepage, preferred search engine and parameters of shortcuts for various installed utilities. The objective in all of the above cases is the same, that is, to make sure Start.qone8.com or Search.qone8.com is visited on the affected computer. Because of the distorted configuration, these hits take place immediately after the web browser is opened, also when the victim looks something up using the quick online search function, and once applications whose shortcut settings have been changed get executed. This flood of forced traffic has got a perfectly tangible reasoning behind it. The people who run the Qone8 malware campaign obviously make a heck of a living out of sponsored links inserted in every search results page at Start.qone8.com. Unethical web traffic generation, plus ads above the fold – that’s the key to the bad guys’ success. There are no options other than removal of Qone8 virus if it infiltrates a PC. This process is not trivial, presupposing a number of combined actions over the malfunctioning web browsers and the use of other troubleshooting techniques. Guaranteed cleanup success can be achieved if instructions on reliable security resources are followed. Source: http://soft2secure.com/knowledgebase/qone8-com-virus