Brownian motion

around the essentials…


Archive for 14 січня 2009

HTB/8021q: That was my fault

Regarding the problem with shaping vlan-tagged traffic on linux bridge — it was my fault :-)

I asked, and Sergey Vlasov answered me with some info and hint — thanks a lot!-)

As Sergey told, «a packet is being passed to bridge module before 8021q can process it». That’s why the classifier decides that a packet does not match a filter rule — because filter contains «protocol ip» condition, however a packet contains «protocol 802.1q» actually. It look like it’s enough to use «protocol 802.1q» in filter condition — after that ip addresses (offsets from IP packet’s start) will be counted correctly.

This offers a possibility to build «aggregating shapers» on linux bridges, which will be able to shaper clients” traffic regardless of «traffic direction» (regardless of a particular vlan membership). And it will be very easy to migrate from an «usual» shaper on linux bridge — we will have to replace «protocol ip» with «protocol 802.1q» in a filter template (or we can add one more filter — if it is really necessary).

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Just mood

I liked just a couple of their songs, or, rather, the manner.

But… *That* time was horrible. Really.

ps. Red sunrise is followed by brown sunset…

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Problem with shaping vlan-tagged traffic on linux bridge

Update: there are no any problem with vlans in classifiers, that was my fault.

Have been playing with shapers and run into such a problem: u32 classifier does not work (?) for tagged traffic on «non-tagged» linux bridge.

In more details:

Test bed:

Let’s take three linux boxes. One will be two-ports switch (SW), on two another (BoxA and BoxB) we will configure IP addresses and, for example.

So.. For the beginning BoxA should ping BoxB on crossover cable.

» Read more — code and comments… »

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Aren’t we going to loose something?..

If the future needs us — in a which way?..

… already for a long time humanity is the human-machine system, which only in this state can perform its functions. If we look at trends, we can see that part of this system’s information, which is being stored outside of human brain, is gradually increasing during thousands of years already — since the invention of cuneiform script — and we simply are closer and closer to that time, when this part of information in a human will become negligibly small.

But do not separate humans and computers — they, along with printed books, are parts of the single system, which can not work otherwise.

Yes, independent can be only that, what can reproduce itself. So, what reproduces itself now? Human? Not at all. Independently of the rest of humanity modern human will die in a few weeks. Reproduces itself the civilization — along with the necessary people, who are reproduced exactly as a machines. … Simply in a some step some elements of evolutionary system can become unneeded — how steams became unneeded some time before, — with the exception that those elements will become we, humans.

However, is it possible to stop progress? Definitely, total control over all planet is necessary for this.

(Translation from russian is mine, sorry for my english)

I would note, however, that i am more optimistic.

Everything will stop before robots will become humans and humans will become robots ;-)

However… we will see.

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