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Goodbye, Ctrl-S

pe1chl Re:Bah, we already said goodbye to CTRL-S years ag (521 comments)

:w or :wq writes the file even when nothing has been changed.
ZZ or :x only writes when there was a change.
It is better to get in the habit of using ZZ or :x only, so that file modification dates are not touched when no change was made.

It is not really required to "just save your progress" as vi does that anyway. When it (or the system) crashes you
can normally recover your file from the tempfile it creates. Writing the file is only required when you want to pick it up in
some other program but not want to leave the editor.

about 8 months ago

OpenSUSE To Offer Rolling Release KDE Experience

pe1chl Re:State of openSuse? (51 comments)

Do you run it for more than a single day at a time?
I have huge memory leak problems. Admittedly, my 2GB RAM is not a real lot today, but after 10 days
of uptime there is 1.4GB of swap in use and increasing. Processes like kded4 and kdeinit4 are huge.
More memory is on the way, but at this rate it is not going to help much.

With a previous (KDE3) install I could keep the system running (and logged in) for 6-12 months without
such problems.
I read that others using KDE4 have had this problem for several years, and nothing has been done.
What gives?

about 10 months ago

DDoS Larger Than the Spamhaus Attack Strikes US and Europe

pe1chl Re: Why are network providers allowing FORGED pack (158 comments)

Users of the internet should send traffic from their assigned address.
When they have multiple addresses they should use the address that belongs to the interface they send it on.
Either they route the traffict to the interface that belongs to an address, or they assign the source address depending
on the interface they want to route on.
Don't adhere to this rule and you face blacklisting of your traffic.

It is similar to open SMTP servers. Used to be no problem, used to be common practice, is not acceptible anymore today.

about a year ago

DDoS Larger Than the Spamhaus Attack Strikes US and Europe

pe1chl Not only NTP (158 comments)

This case mentions the use of NTP, but the idea of reflection attacks by now has propagated to TCP as well, even without amplification it seems worthwile.
Right now an attack is running on many webservers that sends SYN packets with source port 80 and 443 and destination port 80 from spoofed source address.
Apparently they want to overwhelm the victim with SYN ACK packets from reflectors.
However, those are the same size as the SYN packets sent by the attackers. Probably no issue, those attacks are likely sent from compromised systems and botnets as well.

It is about time that a blacklisting system is setup for providers that allow source address spoofing, similar to how providers running open SMTP servers were tarred and feathered until they fixed it.

about a year ago

DDoS Larger Than the Spamhaus Attack Strikes US and Europe

pe1chl Re:Why are network providers allowing FORGED packe (158 comments)

That is called ip spoofing. They send a request with a sender address of a victim, and the server sends the reply to the victim.
This would not be possible when the attacker's ISP would not allow source address spoofing.

about a year ago

DDoS Larger Than the Spamhaus Attack Strikes US and Europe

pe1chl Re:Why are network providers allowing FORGED packe (158 comments)

"I found-out the hard way, several of my customers were sending outbound traffic with source addresses not on my network."

You should lose those customers! Really.
No-one, I repeat no-one, has business sending packets with forged source addresses.
Refer them to a book on policy routing when they don't know how to route in a multihomed enviroment.

about a year ago

Finnish Hacker Isolates Helicopter GPS Coordinates From YouTube Video Sounds

pe1chl Re:It's just 1200baud 7O1 Bell 202 (163 comments)

But that is not because it hasn't advanced much. It is because first it advanced a little bit, and then it mostly died
when internet came to the homes and the novelty of packet radio was taken over by internet applications.
What is now left are only the most stubborn users, the same ones that never advanced to higher speeds.
But the usage is not more than 1% of what it was in the nineties. Relative to what is left, 1200 baud still plays a
major role. But not relative to what there was in the nineties.
(at least that is the local situation here)

about a year ago

Finnish Hacker Isolates Helicopter GPS Coordinates From YouTube Video Sounds

pe1chl Re:It's just 1200baud 7O1 Bell 202 (163 comments)

She mentioned that she used a spectral analysis to deduce that this was 1200/2200 Hz FSK, well I knew that by just listening to it!
This is exactly the same sound as 1200 baud AFSK amateur packet radio made in the eighties/nineties, indeed using Bell 202 AFSK modems.
I have heard so many of those packets while seeing them scrolling by on the screen that I can sometimes hear what kind of packet it is by just listening. (of course not the exact content)
Only in this case it is async serial data, while with packet radio it was HDLC NRZI-encoded sync data. And because in packet radio there are alternating transmissions from different transmitters, you hear a characteristic "leader" pattern similar to the idle pattern in this broadcast followed by a data packet and a keydown of the transmitter.
She probably was at an advantage not knowing about this, as she did not waste time to see if it was HDLC.

about a year ago

Ask Slashdot: Has Gmail's SSL Certificate Changed, How Would We Know?

pe1chl Re:Expiry (233 comments)

Unfortunately it issues warnings all the time, especially for google and twitter.
They occur so often that you (or at least me) get the habit of accepting them without further checking, to be able to continue working.
This largely defeats the usefulness of this add-on.

It appears that google twitter use different certificates on different servers around the world, and you get those warnings when
the loadbalancing mechanisms direct you to another server you were using last time (for the same domain name).
Either that, or their communications are intercepted by the local security agency who acts as a man-in-the-middle.

How would you know?

about a year ago

Transportation Designs For a Future That Never Came

pe1chl Re:Mass transit (120 comments)

Highspeed rail in the Netherlands. We have a small country, so when a highspeed rail
is constructed every city wants a stop along it, and cities are only 30km apart here.
Furthermore, when they ask me "would you take the highspeed rail to Paris" I probably
would answer yes, but it would not be more often than once every 2 years or so. Not a
basis for a regular train service.
So what we got was a highspeed rail with a surcharge, nobody using it so they had to
stop the regular service to force the users over to it. There was a special train built for
"local" service, but it had so many defects that it was removed from service and there
now is a big dispute with the manufacturer.
The problem with trains is that everything is so close here, and people who can afford
the ticket price normally can afford to travel by car and have the advantage of door-to-door
travel. E.g. the highspeed rail would be ideal for government officials to travel to Brussels,
but I'm sure they use their car-with-driver instead.

about a year and a half ago

Transportation Designs For a Future That Never Came

pe1chl Mass transit (120 comments)

Even those ideas for mass transit that did work out are not always a success.
It appears to be difficult to predict the usage of such a network.
We got a highspeed rail line but nobody is using it. Existing connections had to
be terminated before some people forcefully started using this train (at higher tariffs).
And specially built trains that were ordered for a lower priced service were a total disaster.

about a year and a half ago

Backdoor Found In OpenX Ad Platform

pe1chl Ad blocking (43 comments)

I had already blocked all ads served by openx servers (by URL regexp) long before this, after a couple of bad happenings on ad sites running openx.
It apparently is an unreliable platform. This finding only proves that.
However, I also think the ad platforms should make 5 steps back to become credible and acceptable again.
An ad server should be called from some customer-specific URL on the website and then serve a JPG or PNG with the ad. Period.
All the hoopla with javascripts fetched from different places, iframes, active content (like flash) etc has made it into an unreliable
piece of junk that just asks for being blocked. When I block it, they should not blame me but blame themselves.

about a year and a half ago

WWVB Celebrates 50 Years of Broadcasting Time

pe1chl Re:Accuracy... (97 comments)

For some time I plotted the jitter of reception of DCF-77 (a similar transmitter in Germany) and I found there was a clear cycle of increase and
decrease of the jitter of the pulses output by my receiver (measured over one minute) over the day.
At daytime the jitter is around 20us, at nighttime it is more like 200us.
This is most likely explained by path length variations that apparently are depending on propagation.
(although texts about such transmitters often boast that there is no propagation effect like the one seen at shortware at those frequencies)

The claimed accuracy is of course at the source, and maybe when you started receiving WWVB years ago and perform some kind of averaging
over a long interval, you could eventually get an accuracy like that, but there is no way it can be achieved over short intervals, let alone for
individual second pulses.

about a year and a half ago

India To Send World's Last Telegram

pe1chl Re:MIGRATING (205 comments)

Actually, companies like Siemens recognized even in those days that lowercase is easier on the eye than UPPERCASE and many
of their telex machines printed only lowercase.

about a year and a half ago

Oracle Discontinues Free Java Time Zone Updates

pe1chl Re:How about distributing timezone info through DN (405 comments)

You query for a location+timestamp and you get a timezone rule back that includes a timestamp range it is valid for.
This information you cache locally, and before making more DNS queries you check of you have locally cached info for that location for which the requested timestamp is within a previously returned timestamp range.
That does not sound too difficult. It is much like the operation of the existing library, which uses a static table instead of DNS queries but still needs to have
separate information for different timestamp ranges.

about a year and a half ago

BBC Clock Inaccurate - 100 Days To Fix?

pe1chl Re:BBC time == UK time - whats the problem? (487 comments)

Of course this is true when you see a clock in the picture, but when I tune to the BBC and press the info button on my remote, I still see the overlaid clock in local time.
And when I press the EPG button to see their schedule, I see the schedule expressed in my local time. So "the nine o'clock news" airs at 22:00.

This is possible because this data is all transmitted relative to UTC and my receiver translates it to local time. And it only works because I cared to set
the timezone for my receiver when it went through its initial setup wizard.

What they probably are worried about is the viewers/users who do not have things like this correctly set.
After all, when your PC clock is not correct and you are on internet, you must have done something wrong. Probably set the timezone incorrectly.
(home versions of windows are by default synchronizing their clock to time.windows.com and Apple stuff probably is no different)

about a year and a half ago

BBC Clock Inaccurate - 100 Days To Fix?

pe1chl Re:Not-so-accurate source (487 comments)

Right now their problem is that people with their clock incorrectly set will see an incorrect time.
They probably don't want to change that into a situation where people with their timezone incorrectly set will see an incorrect time.
(as that will probably largely be the same group of people)

about a year and a half ago

Massive Email Crash Hits Canadian ISP Shaw

pe1chl Re:Things like this (150 comments)

In a recent programme on local TV, some investigative journalist reported that they had found many
NAS devices online. A certain brand of NAS comes with sharing enabled by default, with a default password.
You just need to unpack your NAS and connect it to your local network and all the data you put on it
is accessible to the world. It uses UPNP to overcome the NAT problem.

The journalist found several NAS boxes with backups of very private data on it.
Another issue is the HP all-in-one printer/scanner devices, which also are internet connected by
default (even via WiFi). So you can access them from your smartphone, how convenient.
But they found people who had left private documents like account activation letters on the scanner,
and could remotely start a scan and read the document.
The users who were contacted were not aware of any problem.

So, it is a big security risk. But to have this work in the case you know what you are doing and
purposely want to share your data or your device, you need the possibilty to contact your port 80.
So it is no good if the provider blocks this with no way to unblock it.

That is forbidden here. A provider must give transparent access when the customer wants that.

about 2 years ago


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