Good Morning from my Robotics Lab! This is Shadow_8472 with a side project of the week. Let\u2019s get started!<\/p>\n\n\n\n
My house has been having intermittent electrical issues for a while, but they flared up enough to diagnose a couple weeks ago. It affected our computer room and the downstairs\/backyard lights. Kitchen appliances and most other outlets were on other breaker circuits, thankfully.<\/p>\n\n\n\n
It was Monday afternoon. Last week\u2019s post was up, and I was tentatively researching February\u2019s big project. My sister, Taz, asked for help moving her workstation to another room and off the faulty circuit. She warned me about her outlet sparking, so I equipped some leather gloves before I began jiggling out her UPS.<\/p>\n<\/div>\n\n\n\n
UPS:
Uninterruptible Power Supply.<\/p>\n<\/div>\n<\/div>\n\n\n\n
The outlet crackled as blue arcs flashed within the empty, upper socket and along the blades of the UPS plug as I wrestled with it. The room lights flickered off a few times, adding to the gut feeling I was aboard a starship, working over a console ready to explode in my face.<\/p>\n\n\n\n
I put an amount of effort befitting a temporary relocation while arranging Taz\u2019s computer. The challenge was her Internet connection. With OpenWRT fresh in my mind, the hardest part was deciding on a previous project SD card to overwrite.<\/p>\n\n\n\n
Each card\u2019s identity was easily confirmed by mounting it and checking <disk>\/etc\/label. One Raspberry OS install stuck out as redundant now that I use BalenaEtcher for disk imaging.<\/p>\n\n\n\n
We quickly ran into an important gap in my networking knowledge: DNS. I shelved PiHole last week in part because I couldn\u2019t get OpenWRT\u2019s DHCP server to properly advertise it as the DNS server. Manjaro\/KDE was mostly in last week\u2019s attempts \u2013 even allowing for a DHCP IP with a manual DNS, but Windows\u2019 \u201cmanual\u201d IP configuration got wiped each time I tested \u201cautomatic (DHCP)\u201d. This led to confusion and frustration when Taz saw our hosted Minecraft server online, but not the authentication servers for lack of DNS.<\/p>\n<\/div>\n\n\n\n
DNS:
Domain Name Service \u2013 translates URL\u2019s into IP addresses, a \u201cphone book\u201d for computers<\/p>\n\n\n\n
DHCP:
Dynamic Host Configuration Protocol \u2013 Automatic IP address configuration, a matradee for networks.<\/p>\n<\/div>\n<\/div>\n\n\n\n
The electrician gave our sparking outlet a checkup. He said that as first goodie on the breaker circuit, everything else is wired in series. When it shorts, everything else is affected before breaker pop. Our outlet has buckled under a heavy load over years\u2019 time; we\u2019ll minimize its usage until repairs happen this coming week. Fun fact: lights and sockets sharing a breaker is a code violation, but it could have been fine when the house was built.<\/p>\n\n\n\n
In the meantime, I idled a day or two while trying\/failing to fix my DHCP configuration for lack of search terms. OpenWRT\u2019s Lu-Ci web interface strikes a good balance: it\u2019s user-friendly without being baby or admin-proofed. Nevertheless, I took my issue to r\/techsupport\u2019s Discord, where I learned about DHCP-options. So far as I can tell, DHCP-options is just a lookup table. Option 6 specifies a list of IPv4 addresses as DNS servers:<\/p>\n\n\n\n
6,192.168.0.2,192.168.0.20<\/pre>\n\n\n\nTakeaway<\/p>\n\n\n\n
Messing with a sparking outlet the way I did was stupid. A few days\u2019 retrospect told me I should have had a fire extinguisher ready. Editing this the night before posting, it dawns on me that de-energizing the whole breaker circuit would have been better still. I\u2019m thankful nothing happened and that the situation is stable enough to wait for a repair.<\/p>\n\n\n\n
I\u2019m also glad to have learned about DHCP options. Of note, I picked up this week that Raspberry Pi Wi-Fi radios were never going to win any performance prizes. My Internet slowdowns are not just me.<\/p>\n\n\n\n
Final Question<\/p>\n\n\n\n
I’m trying something new by isolating glossary terms in a column. They were a pain to figure out, but I think I can control them now. What do you think?<\/p>\n\n\n\n