What have you learned lately?

TechGromitTechGromit GSEC, GCIH, GREM, Ontario, NY Member Posts: 2,020 ■■■■■■■■□□
I learned what to look for when a switch is having a spanning tree loop / broadcast storm. I was on travel and got a SMS message a distribution switch was down. I pinged the switch and it replied back, but after 10 or so pings it stopped responding, than after 30 or so failed pings the switch replied back. This behavior puzzled me, it wasn't enough time for a switch reboot. I was able to quickly log into the switch when it responded and pull the logs, but it really didn't tell me much other then the down stream switches were not responding. These switches have port channels set up on them, but without bpduguard. The onsite person has limited network troubleshooting abilities, they reported that two switches had failed and needed to be replaced.

Fortunately one of the more knowledgeable network guys was able to log onto the core routers and see that there was a spanning tree loop on the distribution switch, he was able to disable port channel on the router to the distribution switch and turn on bpduguard, shut down the fiber ports for all the switches on the distribution switch and enable them one of a time to identify which switch was the cause of the spanning tree loop. Ended up being a looped unmanaged Linksys switch on a downstream switch what was supposedly "broken"
Still searching for the corner in a round room.

Comments

  • ErtazErtaz Member Posts: 934 ■■■■■□□□□□
    I've learned that my current company's expense process requires me to pay for SANs class up front and then get reimbursed later. Oh well, at least I ran it up on a rewards card.
  • tedjamestedjames Scruffy-looking nerfherdr Member Posts: 1,179 ■■■■■■■■□□
    I learned how to set up a KVM switch at work. I ended up buying and installing a two-port KVM for my wife's laptop and desktop and then doing the same with my PCs with a four-port switch. Got four PCs (two laptops and two desktops) on a switch with dual monitors, sound, and USB device sharing (can print from any PC). I've also set up a homegroup for all four for file sharing. It's nice not having the extra monitors taking up space. It's been a great learning experience for me.
  • markulousmarkulous Member Posts: 2,394 ■■■■■■■■□□
    Deploying Office to a terminal server via a script. Bit of a PITA but got it done finally.
  • LexluetharLexluethar Member Posts: 516
    Learned out to create a PowerShell script that polls computer resolutions based off an Excel spreadsheet. Column A has all computers in our environment, the script reads that value, polls the PC for all screen resolutions then prints the screen resolutions in Column A through F. Easy to poll screen resolution, difficult to loop that and print that data when a device has multiple monitors (at least for a PowerShell novice like myself).

    Silly i know but our SharePoint Admin wanted to know the ratio of screen resolutions in our environment so they could create some websites that look 'best' to the most people.
  • UnixGuyUnixGuy Are we having fun yet? Mod Posts: 4,251 Mod
    I learned that daily team meetings at 9:30am are absolutely useless.
    Certs: GPEN, GCFA, CISM, CRISC, RHCE
    In Progress: MBA
  • tedjamestedjames Scruffy-looking nerfherdr Member Posts: 1,179 ■■■■■■■■□□
    Hey! I used to work for Meeting Guy, too! And Meeting Lady. Meeting Lady used to call them at 7:30 AM. Drag!
    UnixGuy wrote: »
    I learned that daily team meetings at 9:30am are absolutely useless.
  • muneebkalathilmuneebkalathil Member Posts: 148
    Learned Recovering Data from OSX, Reinstalling OSX Capitan and also learnd that Fixing a Windows /Linux Machine is More easier than an Apple system .. :huhu:.
  • the_Grinchthe_Grinch Member Posts: 4,165 ■■■■■■■■■■
    I learned the value of data analytics. Second time I've flagged something and within a month a problem has arisen. Yet I still get complaints about having to comply with an information request :)
    WIP:
    PHP
    Kotlin
    Intro to Discrete Math
    Programming Languages
    Work stuff
  • Node ManNode Man Member Posts: 668 ■■■□□□□□□□
    i've learned accessing switches &routers via a jumpbox is the way to go.
  • scaredoftestsscaredoftests Security +, ITIL Foundation, MPT, EPO, ACAS, HTL behind youMod Posts: 2,772 Mod
    Snapshots are your friend.
    Never let your fear decide your fate....
  • EV42TMANEV42TMAN Member Posts: 256
    I learned how to set up Veeam with Cloud Connect for a multi tenant enthronement and deployed all of it. Just time for Veeam to announce all of their big changes tomorrow which will probably kill half of my design....
    Current Certification Exam: ???
    Future Certifications: CCNP Route Switch, CCNA Datacenter, random vendor training.
  • varelgvarelg Banned Posts: 790
    Network bonding and its modes. There's one at work, on a set-n-forget linux box plus it's an objective for RHCE.
  • NetworkNewbNetworkNewb Member Posts: 3,298 ■■■■■■■■■□
    Cooling off a computer with cold water does more harm than good.
  • dmoore44dmoore44 Member Posts: 646
    That i'm definitely not an economist.
    Graduated Carnegie Mellon University MSIT: Information Security & Assurance Currently Reading Books on TensorFlow
  • chrisonechrisone Senior Member Member Posts: 2,198 ■■■■■■■■■□
    I procrastinate
    Certs: CISSP, OSCP, CRTP, eCTHPv2, eCPPT, eCIR, LFCS, CEH, AZ-900, VHL:Advanced+, Retired Cisco CCNP/SP/DP
    2021 Goals
    Courses: eLearnSecurity - PTXv2 (complete), SANS 699: Purple Team Tactics (completed), PentesterLabs Pro (ongoing)
    Certs: eCPTXv2, CRTE, AZ-500, SC-200 (March 5th)
  • thomas_thomas_ CompTIA N+/S+/L+ CCNA R&S CCNP R&S/Enterprise/Collab Member Posts: 971 ■■■■■■■□□□
    I just learned that certain versions of Cisco IOS have an IOS shell that you can turn on which opens the door for some interesting possibilities.
  • OctalDumpOctalDump Member Posts: 1,722
    How to do a password recovery on a Brocade Silkworm 200E.

    That phone scammers that install remote access tools on your Mac don't do a lot to hide their tracks. And that Google, Apple, and Sophos seem to have given up on Mac OS X 10.6, making it very hard to secure for web use. Which sucks because Photoshop CS5 has 'issues' on 10.7 and higher, so you are left with "Do I want to pay more money for a newer version of Photoshop OR do I want to use the web?"

    That the Emulex LightPulse LPe11002 needs tomfoolery to get to work with Vsphere 6, DESPITE being on the hardware compatibility list and meant to work "out of the box". Luckily someone else had figured out this problem, and where to get the necessary drivers.

    A little less recent, but the Dell PowerEdge 7250 requires special software to be able to install any OS on to it, and that Dell no longer supplies this software because the 7250 is end of life.
    2017 Goals - Something Cisco, Something Linux, Agile PM
  • ananth234ananth234 Member Posts: 10 ■□□□□□□□□□
    I am learning about Exchange Server these days.
  • TechytachTechytach Member Posts: 140
    Learning C#. I know I said I was going to try python at one point, but something drew me to C#. So far I've learned to make a few simple applications like a calculator. I'll probably work on a simple app that connects to a dummy database next. Just so I can say I've worked with SQL.
  • v1ralv1ral Member Posts: 116 ■■□□□□□□□□
    Learned how to unlock the built-in local admin account on all Windows machine's at work using Kali. Also learned how to setup a DMVPN network and route redistribution.
  • TechGromitTechGromit GSEC, GCIH, GREM, Ontario, NY Member Posts: 2,020 ■■■■■■■■□□
    Spent a couple of days figuring out a crap whitelisting program called Lumension Endpoint Protection. Had to upgrade Symantec due to a security vulnerability, but a group of computers were protected by Lumension. With no training, a spotty directions, I was able to puzzle the program out enough to unblock policy, upgrade Symantec, Whitelist and apply blocking policy again. Anyone else ever deal with this Piece of S__t software before?
    Still searching for the corner in a round room.
  • pevangelpevangel Member Posts: 342
    I just learned that the voucher I received to take the JNCIA for free works with a JNCIP.
  • JustFredJustFred Member Posts: 678 ■■■□□□□□□□
    Don't stick around too long if the job you were hired for turned out to be something totally different. Have it in writing
    [h=2]"After a time, you may find that having is not so pleasing a thing, after all, as wanting. It is not logical, but it is often true." Spock[/h]
  • TheFORCETheFORCE Senior Member Member Posts: 2,298 ■■■■■■■■□□
    I learned that a lot of our software is outdated and unpatched. Whixh makes my life busy since everything has to go through change control.
  • rob42rob42 Member Posts: 423
    I’ve learned that not everyone that asks for help and advice, has the common decency to thank those that provide that help and advice.

    Edit to add...

    I've also learned that CPT is no substitute for a physical lab.
    No longer an active member
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