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today I’ve met CCDE practical exam heads-on in London. it’s a new one at the Expert level, focusing on designing and redesigning of the networks - according to the virtual needs of virtual customers. after the Networkers CCDE presentation delivered by one of the authors of the CCDE program - Russ White - it’s hard to expect anything different than what they say. it’s very focused on “why”, and “how” is touched only in some generic terms. in other words, CLI-masters will get bored, but you’ll spend a lot of time thinking about subjects like: ...

as you can see, 1GE share in overall switching market started to rise only recently (mainly thanks to cheap NICs and onboard integrations done by Realtek, Marvell, Broadcom and Intel). on the other hand, hunger for bandwidth grows as well - full HD movies from NAS need a lot of it, and if you’re planning to do something in addition to that sourced from the same NAS - it’s even worse (it seems everyone streams nowadays video content to different mobile devices around their homes over WLAN). ...

i’d like to thank everyone that was part of last PLNOG edition. we introduced education track - that was your idea, voiced in chats and in surveys. it seems that the idea was right, so on september PLNOG edition we’ll continue with MPLS and QoS. also according to announcements, we did joint session with Rafał about architecture of ethernet switches and IP routers. i hope you liked it. we still miss real life use case sessions provided by you - service providers. we’ll gladly make room for both success stories as well as failure talks - everything that can be useful for others. ...

some time ago i’ve written a post about displaying live traffic that is going throught the router. also, i covered how it can be split based on autonomous system (with some sorting capabilities built in), thanks to Flexible NetFlow. recently, Flexible NetFlow was extended to use NBAR capabilities, and with that we have new options to sort traffic by application. with slightly modified flow record snippet, we can collect also the application name: ...

good people at RIPE did some testing and it turns out it’s pretty quick!

…hit me again (in a positive way). i was experimenting in my lab and wanted to define a lot of queues (and i mean a lot of them) in ALTQ. unfortunately, very quickly during parsing of pf.conf pfctl barked out following information: pfctl: DIOCADDALTQ: Cannot allocate memory to overcome the problem, you only need to modify those three files: /usr/include/altq/altq_hfsc.h /usr/src/sbin/pfctl/missing/altq/altq_hfsc.h /usr/src/sys/contrib/altq/altq/altq_hfsc.h where #define HFSC_MAX_CLASSES 64 is defined - to requested value. then rebuild the kernel and everything should work as expected. ...

it seems Google decided to reach out to wider community and use the freely available network stack for it’s own MPLS prototyping. the effect is complete MPLS LSR prototype described during recent NANOG 50 talk that’s also available as video. of course it’s quite interesting to see Google experimenting with that kind of solutions - maybe it will be connected to OpenFlow as non-academic exercise? will it become mainstay of new service provider networks? let’s talk about it during next, march edition of PLNOG. ...

IPsec code in OpenBSD is source of constant discussions. it seems there’s no reason to panic (and OpenBSD penetration is anyway minimal), but there’s a lot of interesting discussions and rumours around code itself and it’s origin. in particular i’d recommend to read this short piece (and this tweet) with code references. they demonstrate for the n-th time, that OpenBSD team, and in particular Theo is really building creative marketing and at the same time patch bugs silently without disclosing them. ...

for some time Jim Gettys on his blog is writing a lot about problems caused by buffers, queues and other congestion avoidance mechanisms. you should really read about them. especially, if you’re in this group that believes big buffers solve all of the problems, and dropping traffic is absolute evil. nowadays it should be treated as absolutely normal thing - in most of the real life cases. on the upcoming, sixth PLNOG we may be able to tackle this problem (if there will be space in agenda), and have a shot at myths and legends related to network QoS. and yes, agenda will be out there soon, we’re just closing down last preparations. ...

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. i have 128GB model. this is Samsung device - and specifically MMCRE28G8MXP-OVBL1. it would be all fine and great, but due to the way Lenovo distributes those drives, they land in your laptop somehow stripped from TRIM feature. ...