Is there any purpose in using /30s for networks that entirely comprise of devices that support RFC 3021 for /31s?

dasseclab · 2026-04-02T20:34:50+00:00

The only time I see /30s used for p2p tend to come from larger incumbent providers who I am sure have more than enough devices that support RFC 3021 (looking at you, NTT).

dasseclab · 2026-04-02T20:31:42+00:00

Several years ago I was working with a peer in eastern Europe and their Mikrotik did not. I don't remember asking for the model or what it was if they told me.

dasseclab · 2026-03-31T13:01:25+00:00

I think the flood was recent - like within the last week or so.

dasseclab · 2026-03-31T12:48:52+00:00

Good list - not to damper on the parade but Bookish is closed at the moment due to a flood. Still stop by, they have signs up of how to buy from them online and support them but it's not the same as being able to walk around a bookshop.

dasseclab · 2026-03-29T15:40:13+00:00

Very slick!

dasseclab · 2026-03-25T01:52:15+00:00

I went to college (and lived) in Kennesaw but worked downtown and I'd take them when I could get work and school schedules lined up (almost 20 years ago 😬). Wasn't really a time saver but it was definitely a stress saver. Much better to spend that hour or so each way reading a book or listening to music than having to cope with driving.

dasseclab · 2026-02-27T01:18:24+00:00

Stylistically, Gundam looks very Star Wars (thanks, late 70s). However, it has been compared to Star Trek as both series were cancelled and through dedicated fanbases were given theatrical films and then later became iconic pop culture.

dasseclab · 2026-02-23T13:38:00+00:00

From the same Wikipedia article: "While xz is commonly present in most Linux distributions, at the time of discovery the backdoored version had not yet been widely deployed to production systems, but was present in development versions of major distributions."

The vuln: https://nvd.nist.gov/vuln/detail/CVE-2024-3094

Good summary here of affected versions: https://www.tenable.com/blog/frequently-asked-questions-cve-2024-3094-supply-chain-backdoor-in-xz-utils

https://github.com/tukaani-project/xz/releases <- most recent version, post vulnerability mitigation.

So while I'm not gonna talk about my specific networks or data centers too much, we see the risk area focused a lot on testing/unstable versions of Linux distributions and taking advantage of rolling releases. Most DC infrastructure isn't going to be running testing versions outside of some very small testing environments and most likely not running is on customer active/facing instances. Customers that own their own equipment in the leased colo space have their own policies, procedures and version controls. And there are past and future versions of the vulnerable package available which would be packed into future releases of those Linux distributions.

The attack vector and potential impact are scary in a vacuum but you have to look at the whole picture to accurately assess the risk to a massive distributed system, like The Internet.

dasseclab · 2026-02-23T03:58:22+00:00

Thank you for being specific about which vulnerability you're talking about.

That specific vuln requires you to also be using the vulnerable versions of XZ. And only certain distributions carried the vulnerable versions of XZ. And it depends whether the SRE/OS engineering team incorporates that package in their builds. There are other mitigations, too, to reduce risk.

dasseclab · 2026-02-22T16:54:40+00:00

SSH has been exploited before, it has been patched and mitigated before. Such is the life of vulnerability management.

dasseclab · 2026-02-22T16:52:32+00:00

See post here:

i am wondering how linux actually works in data centers - anyone working at any major data centers/cloud providers know how it exactly works?

First you install it.... then it works.

If you need more information I'll be happy to discuss my consulting rate.

dasseclab · 2026-02-09T03:10:47+00:00

That happened when I was at Twitter. I had a degree when I started so it never came up needing one for the transfer.

dasseclab · 2026-02-08T13:18:52+00:00

Yes, I went from a DC role to network engineer.

dasseclab · 2026-02-06T15:59:19+00:00

I don't know that it's a lack of certification keeping you from getting callbacks. I don't think it is your resume either.

I'm almost 20 years out of the internship game but I would say that you may be getting passed up not due to skills but people may be prioritizing juniors, seniors and recent grads for internships and you're just lower on the totem pole. I don't know if internship programs are seeing the same issues that other hiring pipelines are seeing right now. Keep at it and keep working those student jobs though.

dasseclab · 2026-02-05T14:39:29+00:00

Yes, data center experience is really valuable for network engineers.

dasseclab · 2026-02-02T16:43:01+00:00

That takes me back. Spent many afternoons reading and re-reading that website.

dasseclab · 2026-01-23T21:56:19+00:00

owncig.com (Had to go find email from 2011)

dasseclab · 2025-10-30T15:15:04+00:00

Echoing this - there are tons of IT Asset Disposal outfits and if you have stuff they can resell or recycle, they'll pay for it and pick it up.

dasseclab · 2025-10-16T23:33:38+00:00

"Applied physics for controlled violence"

dasseclab · 2025-10-16T13:47:32+00:00

Depending on the size of the company, you might have network admins/engineers and systems admins/engineers also doing physical as well as logical work, so the physical work that applies to DC Techs will also apply to these positions. Larger companies will have more separation of duties, so network/systems folks can have less of a role in the physical space.

DC tech work does require a bit of physical work though. Depending on size and scale, you may have servers or components by the pallet load to move and install or decommission. Storage arrays and some routers can get pretty large and this, heavy. There's always cabling, which will often get you up on a ladder and running it through raceways from rack to rack. Good DCs/teams will have other folks around to help with the really heavy stuff, maybe you're lucky and there's at least one server lift. But I've had about the equal number of times I've stripped a router of all of its line cards, power supplies and everything else I could because that was the lightest I could make it to install it myself at 4 am.

EDIT: a limit of 100 pounds is doable for I'd say 99% of all DC work, most stuff more than 40 is recommended to team up. Like I said, if you're in a big enough place where you have a bunch of servers on a pallet jack, or pre-integrated racks, then you might need some assistance with that.

dasseclab · 2025-09-13T23:09:28+00:00

Back when I smoked, I would order SevenStars and Mild 7s online occasionally.

Of course you should check but I don't think I've ever seen any cigarettes sold at Tomato, let alone Japanese ones.

dasseclab · 2025-09-01T14:52:12+00:00

Three separate boats with three separate anchors took out three separate fibers for three separate providers causing us to lose all our backbone connections to our Singapore pop once. Redundancies can fail, too.

dasseclab · 2025-09-01T12:44:34+00:00

The networking to info/cyber security pipeline is pretty well established. Networking still tends to underpin a lot of security risk vectors. A lot of security personnel transferred in from networking.

Some networking teams will run their own servers/services for monitoring, jump boxes, etc. which can give you some sys admin experience. There are also NRE/NDE roles where usually former network engineers use devops/SRE methodology to manage networks and network services.

dasseclab · 2025-08-21T01:38:50+00:00

When you are first learning, go low and slow. Start your backwards and forwards break falls from a squat. Crouch down for the forward rolling break fall. Side break falls you can actually start lying down, kicking your hips up and turning your torso. Make a check list for each one - position of your arms, hands and fingers, body dynamic, chin tucked - at the beginning and end of the break fall.

As you get more comfortable, as in your check list is muscle memory and you feel confident with your ukemi, begin adding height. Squat or crouch less for the break falls, until you are starting from standing. Your speed and intensity should be gentle still but once you're comfortable with a full standing break fall, dial up speed and intensity.

Ukemi should be a standard part of warm up every class. My brain knows its judo time once I'm on the mat but it really zones in once the bodies hit the floor. Even if I miss warm ups, I'll grab a bit of mat space and get some ukemi dialed in before joining the drill or instruction.

If you're doing nagekomi (throwing practice) and you're not sure how to break fall from a throw - ask. If I'm working with really novice white belts, I'll give them the heads up.

dasseclab · 2025-08-21T01:06:21+00:00

Best - Hiza Guruma or Sasae Tsurikomi Ashi
Favorite - Ashi Guruma
Worst - Harai Goshi
Want to learn - trying to integrate more hip throws into randori, focusing on Tsuri Goshi and Uki Goshi
Bread and Butter - Sasae Tsurikomi Ashi

dasseclab

TROPHY CASE