Posts

Week 10

This week we discussed some of the tools available for troubleshooting networks not behaving properly.  One of the physical tools available is called an Optical Time Domain Reflectometer (OTDR) which is used to detect where a break in a fiber optic cable has occurred. It in essence sends a very fast pulse of light down an optical cable and measures how fast and how much light returns. When light hits a break in the cable, some of the light will be reflected from that point. Since light has a well defined speed, we can use the time from the transmission to the receiving to figure out where a break in the cable is (or that there is in fact a break in the cable at all, and there is not some other factor in place). This information can be used to repair the cable or determine if it's better to just pull a new fiber in its place.  There is a similar tool called a time domain reflectometer which sends pulses of electricity down a copper cable. Similarly, this can also tell you where...

Week 9

While documentation may be one of the most preached practices for network and computer techs alike, it also seems to be one of the most neglected. Techs often forget to write documentation at all or write objectively bad documentation with not enough information to help the next guy. I have started trying to get better at this myself and have taken to writing notes whenever I come across a problem I’ve never seen before and am working on creating documentation for well established processes that have never been documented, or have changed since the last documentation. We have also implemented a new ticketing software that allows you to write internal notes and such on tickets which can be useful to refer to in the future.

Week 8

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This week we discussed cloud computing and virtualization techniques. I guess that gives me the opportunity to talk a little more about my mini homelab setup again! (I'll tie it into the topics discussed this week at the end, don't worry.)  Since my first week blog post, I was able to add a sub panel (shown in the second image), and some dedicated outlets in the closet that I am now using for the rack, instead of having to run an extension cord from the basement under the door.  I've added a locking L6-20R (20 amp 240V receptacle) (left) for the 240V UPS I eventually intend to get (once I feel like wasting about 700 bucks, dang those things are expensive), but I used 12-3 wire so I can easily upgrade the receptacle to L6-30R (240V 30amp) or L14-30R (Combination 240v and 120v 30 amp) if necessary. I also added a locking L5-20R (20 amp 120V receptacle) (middle) which I am currently using for the 120v UPS in my rack, as well as a standard 20 amp receptacle for anything else I ...

Week 7

While we’re on the topic of setting up Wi-Fi networks this week, I figure it may be prudent to discuss a topical issue happening in the US regarding the future of the 6 GHz frequency band employed by Wi-Fi 6E and Wi-Fi 7 technologies. The One Big Beautiful Bill Act introduced by the Trump Administration goes over several policies that aim to cut government spending and do a whole bunch of other things that are out of the scope of this conversation. The part of this bill that is in-scope relates to section 400002, spectrum auctions. This section specifies that the FCC is supposed to look at all frequencies between 1.3 GHz and 10.5 GHz and come up with about 800 MHz that can be sold to the highest bidder for licensed uses. The problem comes from two additional facts: some sections of the spectrum are off limits, and other sections are already in use by well-established standards like 2.4 and 5 GHz Wi-Fi and changing those standards would be impractical at this point with the numb...

Week 6

The instructions for the blog post say not to just copy discussion posts over, but we’ve only talked about one thing this week: IPv6 addresses, and the incredibly large number of addresses created with 2^128 bits is very fascinating to me so I’m doing it anyway! (Though with a few different examples than the discussion post). IPv4 addresses use 2^32 bits to store the information which gives you a little over 4 billion addresses. Since a billion in and of itself can be quite difficult to comprehend, let’s talk about a billion dollars for a second. If you made $100 a minute ($6000/hr) every day of your life, that would equate to $144,000 a day. Even with 4x my annual salary in a single day, it would take you 19 years to get up to just one billion dollars. Expanding on that, we can determine that it would take you 81.7 years to reach the amount of IPv4 addresses we have available. (On a side note, how much is Elon musk making to be evaluated at almost 400 billion dollars? With your *pat...

Week 5

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This week I would like to discuss the hosts file that used to be the directory for the entire internet.   Back when the internet was just a baby, the ‘hosts’ file was a file placed on every computer that was connected to the internet that had a list of IP addresses and friendly names for all other computers also connected to the internet. Every day at 2 AM, this list would be updated with any new computers that had been added. Of course, this system quickly became unsustainable and had to be replaced with a new system which later became known as DNS. Interestingly, this hosts file still exists on all computers today, and still works just as it always had, albeit you (or your system administrator) are now the people in charge of maintaining the list. One use for the hosts file that I have found recently is the Remote Desktop Connection app used within Pro versions of Windows. I’m not sure when the setting became a thing, but on the ‘Advanced’ tab on the connection dialog box is ...