Nexus and ECMP for DNS

if you read my previous pieces about my home network, you know well my core switch is Nexus 93180YC-EX. you know… home, core switch. anycasted services at any point in time I have a number of DNS (and DHCP) servers available, all reachable via either or 2001:470:xx:a6::168. no matter what is going on, at least one should be able to respond. currently, in the “cluster” I have two VMs and two physical Raspberry Pi 4B+....

January 29, 2024 · Łukasz Bromirski

FreeBSD on Raspberry Pi 5

if, like me, you would like to use RbPi 5 and FreeBSD at the same time, simply copying the 13.2/14.0 image to the SD card is not enough. in addition to the already known one (where rdiskX contains the ID of your SD card/USB key - beware of accidentally overwriting your system drive or another data drive): $ xz -dc FreeBSD-14.0-RELEASE-arm64-aarch64-RPI.img.xz | sudo dd of=/dev/rdiskX status=progress bs=64M 5368709120 bytes (5369 MB, 5120 MiB) transferred 261....

January 16, 2024 · Łukasz Bromirski

casual MacOS TCP tuning

ever since the initial tuning of the FreeBSD TCP/IP stack around version 4.x, I’ve found myself occasionally tinkering with the contents of /etc/sysctl.conf just to fine-tune things, you know over time, numerous changes have been made to the FreeBSD TCP/IP stack, including the introduction of modularity. however, MacOS X, being based on FreeBSD, is more conservative and lacks certain options. therefore, on my MacOS systems, I make use of the following /etc/sysctl....

September 3, 2022 · Łukasz Bromirski


recently during casual browsing of WLAN controller i spotted that sometimes users are having problems with receiving responses from DHCP server. i was suprised, as family doesn’t complain - and they’d do that immediately. well, so i went troubleshooting element by element. obviously, switches were primary suspect. why? everything was working, and those DHCP problems were very, very rare - that may mean drops on switch interfaces. Cisco QoS configuration on Catalyst and Nexus switches is far from easy....

August 29, 2020 · Łukasz Bromirski

you can't get enough space and speed

my 256GB SSD drive in MacPro 2013 started to fill up recently. i went on short googling to see how to extend it without relying on NAS of course. and i get nice offer. it seems that good people in the internet found a way to interface typical NVMe disk drives with the socket Apple uses. and so i became user of 1TB Samsung SSD drive. that upgrade gave me also speed bump - on encrypted drive transfers shoot up from 500MBbs (reading) and 380MBbs (writing) to 1....

March 12, 2018 · Łukasz Bromirski

please clock me timely!

during the last 30 years, processor speeds has increased from millions of cycles to billions - multiplied by multi-core and special mechanisms that increase the efficiency of working with ‘boring’ cores. Pentium 66 processor from 1993 contained 3.2 million transistors, which is anyway quite a value, considering they are packed into a space comparable to that of four dices - and contains one main unit. available today Xeon E5-2699v4 has 22 cores operating at nominal frequency 2....

February 8, 2017 · Łukasz Bromirski

world is changing

failure that Tidal came to be and at the same time success to which Apple Watch is experiencing (the same that has trouble keeping it’s bettery up for ONE day) is troubling. on one side we have market, that is able to verify this poor and blatant run for money organized by multi-billionaires, obviously coupled with lack of any style and market research (which would show there are other, better, faster and with wider selection of artists and capabilities services available already), on the other hand - Apple Watch?...

April 25, 2015 · Łukasz Bromirski

gimme more!

quite recently i described my own new workstation. it has dual Xeon processors, and today i decided to upgrade memory from 128GB to 256GB (yeah, i use to run a lot of VMs). so below you can see the outcome - 256GB RAM, 2 physical CPUs, 16 cores, 32 threads: great advantage of having such beast at your disposal is that you simply can run everything thrown at it. it’s quiet, it’s effective and it also doubles as great gaming station....

June 8, 2014 · Łukasz Bromirski

because you can't just have one CPU...

…workstation requires two! ;) i had some time over Christmas to finally build myself following beast: Asus Z9PE-D8 WS (BIOS 5304, original 3304 had some interesting bugs Xeon E5 2660 (Sandy Bridge EP/EX) - 16 cores, 32 HT Corsair H80i for CPU cooling 64GB RAMu (8x 8GB DDR3 1600 ECC) OWC 480GB PCIe - has two 240GB blades in RAID0 Corsair Obsidian 900D 2x Seagate 4TB HDD [6x Samsung 2TB] LSI 9261-8i to drive those mechanical disks in RAID5 Creative SB ZX AMD Radeon 7970 connected to three Dell U2412 monitors Intel x520 NIC connected to Catalyst 2960S and to other workstation - Xeon 5670, 48GB RAMu, OWC 240GB as boot and two 2TB RAID0 disks as RAID0 for ESXi 5....

February 1, 2014 · Łukasz Bromirski

first new year resolution

don’t start your php upgrade at 2:40 in the morning. as you’ll stay awake until 5am :)

December 29, 2013 · Łukasz Bromirski

things tiger dreams are made of

you could meet me sometimes during late night hours on Call of Duty Modern Warfare 2 multiplayer servers. now, i decided to change environment a bit and return to love of my life - flight simulators. i dusted off CD with Microprose Falcon 4.0 and i’m downloading BMS patches while reading about Allied Force (CD is already on my way from one of the Amazon warehouses). i’m still using Saitek Fly 5 but if i’ll be able to find more time to fly - there are couple of better sticks out there....

April 30, 2013 · Łukasz Bromirski

hardware and software integration...

…how tightly coupled should it be? i can’t help to think about it. i’m writing this post on construction that was defended to his last days by Steve Jobs. according to his belief, only software tightly integrated with software can be effective and predictable. independently of what Steve believed, there are other examples of such thinking in the world. let’s take for an example company i work for - Cisco. most of our solutions are based on software integrated with hardware without ability to add questionable “apps” to the mix....

September 10, 2012 · Łukasz Bromirski

beautiful fonts

Google sponsored a interesting project some time ago and shared the open font project with community. it’s not a news per se, but today while looking at one of the blogs I’ve browsed through sources and found out about it :D the concept is pretty simple and I recommend you to have a look at it (I’m using them already as you can see).

August 6, 2011 · Łukasz Bromirski

state of SSD market

after experiencing massive hardware problems with MacBook Pro, i immediately fell into series of mysterious SSD failures. i’m baffled with the state of the (pro) electronics market. first, there was OCZ Vertex 2. my MacBook Pro couldn’t properly work in SATA3 mode despite the fact that Intel controller could. so i moved then to OCZ 2 working on slower SATA bus. it died after week, silently and ultimately. well, RMA submitted, disk will travel to Netherlands and then they’ll send me back working one....

July 22, 2011 · Łukasz Bromirski

OEMing SSD drives

it started in a innocent way - my company W510 started to work slower and slower. as it is very busy usually and i need full performance and every bit of power for daily work, obviously i decided to investigate. Windows 7 x64 installed in a clean and very controller manner, 8GB of RAM available and usually not used in more than 50%. so what’s going on? Lenovo is using SSD drives of a different size....

January 14, 2011 · Łukasz Bromirski

short RAID story

those of you frequently visiting my home site noticed that it wasn’t available for some time. unfortunately, that’s because of interesting RAID 5 failure in my server that hosts also my web page. FreeBSD relentlessly tried to serve web traffic from filesystem that was failing apart because of hardware problems, but then, 30 minutes after first failure, second hard disk failed in the same array! temperature was finely tuned, but it seems that after 5 years of continous work they had to fail....

June 12, 2010 · Łukasz Bromirski

vacations and move

for the next two-three weeks there will be no new posts. i’m preparing move of my server from Białystok to Warsaw. old, tired IBM PII-233 will be replaced by new IBM x306. if everything goes well, you’ll see no change. in the meantime i should be able to push new revision of Cisco FAQ PL plus some other stuff.

July 17, 2004 · Łukasz Bromirski


i dedicate this short article to all pc maniacs.

April 28, 2004 · Łukasz Bromirski