Daniel Dib asked recently on Twitter about BGP convergence time for world wide operations. two hours he got in response from his friend seemed a bit too long. I did recently help to spin up new ASN with new IPv4 prefix (well, both came from second hand, but you get the point) and as far as I could tell, propagation took around 15 minutes maximum. so in the interest of self-education, I started digging. ...
i posted quite emotional piece some time ago - on real world warriors that really don’t need to do anything more than they already did. despite that, they want more. publicity, fame and to achieve that - they use lies. it seems even poster hero of US - killed sniper Chris Kyle did a bit of lying himself. and it seems he was even warned specifically against it by his superior - that he can’t make false claims about number of medals he received. despite that, and despite that America is quite open in areas where they shouldn’t probably be so (well, i’m from Poland, and pre-1989 nobody would even thought on getting documentation about discharged soldiers so easily) so checking such claims can be very easy. Chris DD-214 document differs a bit from his book story and obviously, the story Hollywood wants you to believe. ...
how David defeated Goliath this story started in June of this year. one of Apple AppStore employees made an “error” while reviewing revision of Basecamp authors new app - Hey. David Heinemeier Hansson, one of the Basecamp founders, took it to Twitter David is not only Basecamp CEO, he’s author of series of great books on running teams and companies. he started to relay live on Twitter emails he and his employees exchanged with Apple Application Store team. as Apple takes anything between 15 to 30% of sales cut out of every in-app transaction, they suddenly asked him to include payment option in Hey. David argued, that the app never had and doesn’t plan to have option to buy anything. ...
WD was recently caught red-handed on trying to sell HDDs to NAS duties that use SMR technology without informing about it (and, actually, by actively trying to misled customers and then silence the whole situation). that ended up in lawsuit. while others were also caught trying to do similar things, they backed up immediately, while WD still tried to say that “white is black, you know, really”. ...
one of the interesting and rarely seen configuration options, is ability to have redundant IPv6 tunnel established from source address tracked by HSRP. if you’re limited by other side of communication - in this example Hurricane Electric - to have only one endpoint of tunnel on your side that’s right tool for task. the way this configuration would work, is that router active in HSRP pair will be the one on which tunnel will be active and forwarding. we’ll be demonstrating this on IPv6 over IPv4 example, but tunnel type doesn’t really matter. ...
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. comparing this however to other vendors… there’s really nothing to compare. on one side you can do whatever you want, on the other side - you can shoot yourself in both foots, stomach and then in the head pretty quickly. just assume, that if you haven’t spent couple of weeks labbing QoS on real hardware - it’s area that you shouldn’t wander alone in unsupervised ;) in very simple terms, either use dedicated GUI for managing campus networks - Cisco DNA Center or stop at either enabling QoS globally (mls qos) or disabling it (no mls qos). ...
i had to do a full recovery recently of my sons MacBook and in doing so, i was greeted with rather mysterious message from Apple: the app store download could not start because it has already been downloaded too many times what? after searching (i’m no longer googling) for a while i couldn’t find anything that made sense. after carefully reviewing internet recovery options i finally found a small, but important difference: ...
update this project is still on, but at different IP. please refer to this updated description. old post below recent thread on nanog@ list got me back to old project that i was thinking about long time ago. and here it is - i just launched free-of-charge, load-your-router-with-full-live-bgp-feed service :) if you’re interested in joining the free project, disregard the information below and jump directly to latest version here disclaimer you’re doing this ON YOUR OWN. i’m not responsible for anything on your end and service itself. so if it crashes your router, makes all traffic to follow different paths, or essentially anything that you can’t control - you’re completely on your own. ...
last post in the series about my home lab resulted in a number of interesting emails in my inbox. i have to admit that i really appreciate words of praise. as well as those with constructive, critical feedback :) so after short description what is connected where and how (see link above), let’s focus now on services. first and foremost - remember it’s “always DNS” ;) so let’s tackle that. ...
i was ranting some time ago about slowness in which IT industry is moving from silicon to light, to speed up not only transport of information (we already do that by means of GBIC/SFP/SFP+ modules), but also processing of traffic. there are already means to do exactly that, and we as Cisco are working on delivering such features in next years. i just stumbled upon this article, which deals with doing similar thing but with machine learning - this quote is stunning: ...