Thursday, May 13, 2021

Microsoft getmac and MAC Address (Flashback)

 When troubleshooting it is quite common to get the mac address of the host, server or network equipment for a variety of reasons.

For example, many syslog messages or logs may refer to mac addresses depending on what the error is. If you are working from the switch, you more than likely need to know the mac address if you need to figure out which port the target is for your monitor or span command. And of course if you are using a protocol analyzer, you should always capture with a mac address, when possible.

In this video I review how most people figure out their mac address and how to determine the mac address of another device on the same vlan as you. The issue with this methodology is that in some scenarios you may want to figure out the mac address of a Microsoft device that is on another VLAN.

Using Microsoft’s getmac command allows you to get your mac address as well as a remote system’s mac address. As I mention in the video, this command seems to be using the DCE/RPC protocol, so if you block this protocol on your host, servers, or network you might have an issue with command.

Lastly, you need to know the user name/password on the remote system for this to work remotely.

Hope this helps you with your troubleshooting.




Wednesday, May 5, 2021

Chasing the Ghost - Nobelist Fred Reines and the Neutrino: Review

 

Upon reading the title of this book, you might be tempted to judge it as too technical or perhaps too arcane to be of interest. If so, you would be missing out on a compelling narrative about an exceptional man and his lifelong quest to do something great. Chasing the Ghost – Nobelist Fred Reines and the Neutrino by Leonard A. Cole has just enough physics to interest and motivate the reader, while keeping the focus on the trials and triumphs in Fred Reines unique life. As Fred’s younger cousin, author Cole supplements his family knowledge of the early years with interviews of many prominent and influential physicists who knew Fred personally.


Our world is essentially made of four elementary particles - up and down quarks, electrons, and neutrinos. The latter is the ghost being chased, a particle that passes through the earth as if it were not even there and is extremely difficult (some physicists thought impossible) to detect. A thousand trillion neutrinos pass harmlessly through your body every second, and many of these were created shortly after the universe was born. Fred Reines called them “the most tiny quantity of reality ever imagined by a human being.” With that brief introduction to the neutrino, you cannot help but want to know more about the man who devoted the bulk of his professional life to finding and studying them.


Finding the neutrino was not just about arguing with colleagues at a blackboard covered with complicated equations, it was an adventure involving extreme hardship that covered the globe. Although neutrinos are abundant, so are the cosmic rays that hide their tiny signal. One solution was to go underground, where those rays could not penetrate. From the first detector built by Fred Reines and his colleague Clyde Cowan to the Hyper-Kamiokande equipment currently under construction in Japan, neutrino projects have grown to a staggering scale. The money required, the size of the equipment, the global locations, and the speculative nature of the search all were daunting. Fred Reines had an imposing, self-assured presence which surely helped him to advance such an overwhelming project.


An early chapter in the book offers a brief biography of Fred’s time growing up and his family relationship to author Leonard Cole. In his high school yearbook, Fred wrote that his goal was to “be a physicist extraordinary.” Early on, he loved acting, singing, and whistling to entertain audiences and as a natural showman, he often veered away from the conventional way of doing things. Later, as a college professor, he loved to speak to his students of the connections between science and the arts. He also struggled trying to grasp his place in the world, and for a time maintained a journal to document his daily thoughts and help create a framework for his endeavors.


Fred’s early work at Los Alamos on the Manhattan Project formed connections which would benefit him throughout his professional career. It was also where he developed an interest in the neutrino, and he saw it as a challenge that many physicists believed it was undetectable. He also saw the possibility of a tangible reward, like a Nobel Prize, which would justify his quest to be a successful, renowned physicist.


When Fred’s academic career landed him at Case Institute, he auditioned and was selected as a singer for the world-renowned Cleveland Orchestra Chorus, an avocation he maintained for 3 years. Throughout his life, he seized opportunities to perform in musical plays, his favorite being Finian’s Rainbow. As Woody, he sang the play’s classic final song which suggests that seeking the end of the rainbow can lead to great treasure. This metaphor for scientific research appeared in Fred’s very successful course in physics for non-science majors titled “Rainbows and Things”, where students were taught that scientific inquiry was a core value of humankind.


Fred Reines professional career spanned the decades of some of the greatest advancements of 20th century physics, and author Cole combines the two storylines in an entertaining and insightful way. Fred’s work on the Manhattan Project primarily involved calculating the yield and aftereffects of nuclear explosions. Here he worked with famous physicists like Richard Feynman, many of whom undoubtedly influenced him. One of the anticipated effects of the atom bomb was a huge release of neutrinos, which piqued Fred’s interest.


While the impact of the bomb tainted atomic research for many years to come and caused suspicion about what physicists were up to, it also created a can-do-spirit for scientists to tackle tough problems. This environment probably helped Fred and his colleague Clyde Cowan put together their first neutrino experiment. The contraption started with a 150 ft deep hole located near a planned nuclear blast. They buried a vacuum tank in the hole, suspended their detector at the top, and released it using a small explosive just as the nuclear blast was set off. After about 2 secs of free-fall, the detector landed safely in a pile of foam rubber. When the radiation had safely dissipated, the device was retrieved and analyzed. No neutrinos were recorded, and the subsequent suspension of above-ground nuclear testing shifted Fred and Clyde’s attention to neutrinos emitted from nuclear reactors.


Their next apparatus at the Savannah River Reactor site used 90 photo-multiplier tubes and an 80-gallon tank of detector fluid. The electrically noisy environment made detection difficult and contributed to a “false alarm” when the press seized on their announcement that they may have seen a single neutrino signal. Haunted somewhat by the specter of pathological science, where accepted results are sometimes later proven false, they built a larger system with 1100 gallons of fluid and 300 photo-multiplier tubes. In 1956, they were able to confidently declare that they had indeed detected neutrinos. The growth in scale of the detection equipment leading up to their discovery was a portent of things to come.


In order to reduce the noise from cosmic rays which tended to drown out the neutrino signals, the chase led Fred and his team deep into the earth at the East Rand Gold Mine in South Africa. They battled sweltering heat, poisonous gas, and occasional random rock explosions for a year to record 10 high-energy neutrinos. An independent team at the Kolar Gold Mine in India reported a similar result at about the same time, adding credibility.


By the early 70’s, the neutrino hunt had spread, and when Fred’s team serendipitously recorded a burst of 8 neutrinos from a distant supernova, the Japanese simultaneously recorded 11 such events at their Kamiokande detector. The 1988 Nobel prize for this second type of neutrino overlooked Fred’s discovery of the first, and he was devastated. In the meantime, the Japanese researchers moved on to the Super-Kamiokande, which would contain 50,000 tons of fluid and 13000 photo-multiplier tubes.


Fred gradually disengaged from scientific pursuits, though he still occasionally conferred with friends and colleagues. He had completely given up hope for the Nobel Prize when, nearly 40 years after he and Clyde published their original discovery, Fred won the 1995 Nobel. In spite of his failing health, he was able to travel to Stockholm to receive the award. He passed away several years later.


Fred’s daughter Lisa remembered him as “delightful, playful and looking at the world as full of wonder.” His ambition as a teenager to do something great has been realized in a very big way since his passing. By 2020, there were over 50 neutrino experiments working or under construction throughout the world. Plans are currently underway for Hyper-Kamiokande, which will be 10 times larger than the Super-Kamiokande and is expected by be operational by 2027.


Although I was occasionally confused by the way that the story seems to jump around, in retrospect I see how this “weaving” process served to highlight the connections between Fred’s unique personality, his exceptional life, and the 20th century physicists on whom he had such a profound influence. The personal interviews related by author Leonard Cole nicely enhance the depth and humanity of his portrayal of Fred. He injects just enough well-placed neutrino physics to convey the difficulty and the ingenuity of the chase.


Not only is Fred’s rainbow a fine metaphor for the treasure that lay waiting at the end of his chase, it is also an eternal symbol of the hope and inspiration which guided his life. Both the chase itself, and the extraordinary man who conducted it, make for an engaging story.


Author Profile - Paul W. Smith - leader, educator, technologist, writer - has a lifelong interest in the countless ways that technology changes the course of our journey through life. In addition to being a regular contributor to NetworkDataPedia, he maintains the website Technology for the Journey and occasionally writes for Blogcritics. Paul has over 40 years of experience in research and advanced development for companies ranging from small startups to industry leaders. His other passion is teaching - he is a former Adjunct Professor of Mechanical Engineering at the Colorado School of Mines. Paul holds a doctorate in Applied Mechanics from the California Institute of Technology, as well as Bachelor’s and Master’s Degrees in Mechanical Engineering from the University of California, Santa Barbara.


Saturday, May 1, 2021

Baselining Documentation - Next Step

 After capturing your data, you end up with a trace file. This next step is just as important as capturing the data since you can’t properly analyze or come to meaningful conclusions if you’re not sure where, when and how the data was captured.


This is where Wireshark’s “Capture File Properties” feature comes in. I use this to make notes about the capture such as: and time markers for events, physical location, vlan, contact info if other people were involved and other documents that might have diagrams, config or other info.


As a matter of personal preference, I prefer creating folders with the date and task and put trace files, images, documents, config files, emails and anything else that I feel is helpful. Don’t spend too much time deciding what to put in the folder at the very beginning. I find it easier to add files as I go along and include a brief description why I thought that file was important. For example, I might include the Cisco or computer config to compare after any suggested changes. There is step is entirely up to you.


In the next few articles, I will cover more packet analysis examples.



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