While spammers certainly don't worry about conforming with RFCs, it should be noted that rejecting email based on the DNS is a specific violation of the relevant RFC, RFC-5321, section 4.1.4, which states:
An SMTP server MAY verify that the domain name argument in the EHLO command actually corresponds to the IP address of the client. However, if the verification fails, the server MUST NOT refuse to accept a message on that basis.
That said, it is common practice to do this anyway. The reality is that you will not have reliable email delivery unless the hostname your server issues in the EHLO command resolves to the servers IP address and the IP address resolves back to that same name.
Its open source and available for Linux/Windows/Mac and probably others.
Its conceptually simple, and therefore pretty quick to get started, but there are always new tactics/counter-tactics to learn.
Being open source, there are cheaters. But I've found this to be a minor problem. Most players seem to be honest and when you do encounter someone that appears to be cheating, just switch to a different server.
Its very sensitive to latency, so you will likely find that some servers work better for you than others. Each server has its own combination of rules/options, so you should try out several servers anyway, just to see what you like.
bzflag (www.bzflag.org) is open source, runs on windows and linux, and is small and efficient. It will run on almost any hardware if you use basic graphics. A good video card is required to get the best graphics, but it really doesn't affect gameplay.
It is basically a first person shooter, where each player is driving a tank and tries to shoot other players. But these are no ordinary tanks, they can take on special "powers" like the ability to jump, bounce shots off walls, aquire laser weapons, quided missles, etc.
There are many variations that can be introduced to make play easier or harder or just to change strategies. There is also a Capture the Flag variation.
Its good fun and downright addictive. And its free, so you've got nothing to lose - give it a try!
But even with my "factor of 10" error, I think my conclusions are still valid. It still takes 5 years to pay for itself. I think the bottom line is still: The electricity costs (and therefore potential savings) for either type of lights is so low as to be negligable compared to the extra cost of the LEDs.
You shouldn't have to spend any time debugging the lights if you are replacing them every year (which was assumed in my calculation).
And remember, a burned out bulb is not the only source of failure - a broken wire or damaged connector can happen to both types of light sets.
The aesthetics are certainly debatable, but I don't find the difference in appearance between to the two lighting technologies to be interesting enough to debate.
As for the cost difference: Lets actually run some numbers:
Let's assume a string of traditional lights consumes 100 watts and a string of LEDs consumes nothing. (I think you would agree that both of these assumptions are more than fair to the LEDs).
If we energize the lights 8 hours per day for 30 days during each "holiday season", that is 240 hours per year that the lights are in use.
If we assume an electricity cost of US$0.10/kwh(which is typical around here, but varies widely depending where you live), that is an annual electricity cost of US$0.024. Lets just go ahead and round this up to 3 cents.
Let's further assume that the LED lights would last forever, but the traditional lights need to be replaced each year at a cost of US$1.50. We now have a total annual cost for the traditional lights of US$1.53 compared to the one time cost of US$20 for the LED lights.
That means it will take the LEDs approx 13 years to reach the break-even point against the traditional lights.
And remember, I made all my assumptions in the favor of the LEDs. Real LEDs do consume some power and real traditional lights don't need to be replaced every year and real LED lights will not last forever (the LEDs themselves might, but the wiring, etc will deteriote due to exposure to sun, weather, etc). So, in reality the break-even point is probably much more than 13 years.
If you just crave the LEDs, then go ahead and buy them, but don't try to claim that you are saving money by doing it.
Now I know that LED holiday lights may seem all hi-tech and geeky, but regular ones are so cheap and readily available, the LED ones just don't seem worth it.
The 80 light LED set linked to above costs about US$20 and come only in red. I can go to my local supermarket and get a regular 100 light set for $US1.47 in a variety of colors or multi-colored. For the cost of one LED string, I can buy 13 regular ones, and still have change left over. Thats 1300 lights vs 80 LEDs!! Sure the LEDs are more effiecient and sure, they will last longer, but not enough to come anywhere close to making up the cost difference.
I think a better "Ask Slashdot" would be: Gee, holiday lights are so darn cheap these days, what other uses can we find for them?" (and no, they won't run Linux, and no, you can't turn them into a web server....or can you?)
Is your friend being attacked because he/she is a sleazeball spammer? Be honest!
If that's the reason for the attacks, well, what can I tell you, your friend deserves everything he/she has coming to him/her. Come to think of it, probably deserves even worse.
You might as well ask "My friend keeps jumping in water and is still getting wet, what should he do?"
The database on an AS/400 is not a separate service - it is integrated into the operating system. All files are treated, more or less, as database tables. Any file (in OS/400 terms, a "Physical File") can be queried at any time.
To select files that were created within a specific timeframe, you would dump a list of files and their attributes in a given directory (IBM calls them "libraries") to a temporary file. This temporary file could then be queried as a database table, selecting files with specific attributes, such as a creation date within a given range.
For some reason, IBM has a different name for everything. Here are a few rough translations:
IPL = reboot (Initial Program Load) DASD = disk space Physical File = File/Database Table Logical File = Index/View Library = Directory
At least on IDE drives, using the hdparm tool can greatly improve performance of modern drives. I found my throughput went from 3 MB/sec to 22 MB/sec with just a few tweaks.
Most distros use very conservative settings for the IDE interfaces which will work with just about any old drives, but do not take advantage of more modern hardware. hdparm allows you to activate those advanced features.
tn5250 is what you need. It's been a couple years since I've used it, and back then it was functional, but a little quirky. I assume it is no worse now, and probably much better. At that time, at least, there were a several developers who were very active on the mailing list, often providing bug fixes the same day.
It provides only 5250 terminal emulation, but not all the other stuff (file xfer, etc) that Client Access does.
They have a mailing list archive here. I suggest you browse through it to get an idea of how suitable it is for your needs. Of course, since its open source, you can always just download it and try it out.:)
(I've seen some suggestions to use 3270 emulators. While an AS/400 will grudgingly talk to a 3270, you loose a lot of the functionality that you are accustomed to from a 5250. Not a solution I reccommend)
I've had several Panasonic 900MHz phones in recent years and have been pleased with all of them. In my experience the digital spread spectrum models (Panansonic's buzzword for this is 'Gigarange') seem to offer a little more range and immunity to noise, and I would assume security from snooping. The difference in quality is not great, and if your budget is tight, I would not hesitate to go with the cheaper analog models.
In my opinion, their Gigarange models try to act too much like cell-phones with a deep and complex menu system that is just too awkward. Fortunately, you can just ignore all the 'gee whiz' features and use it as a good ol fashioned phone.
Consumers Reports did a test recently and concluded that there was no advantage to the 2.4GHz frequency over the 900MHz frequency. This has been my personal experience as well. I wouldn't pay any extra for a 2.4GHz phone. On the other hand, if you know you are already using one band (wireless network for example), that may be a good enough reason to get a phone that uses the other band just to reduce interference.
As it sounds like you have an electrically noisy environment, I think the best advice is to buy from a store will liberal return policies. Pick a phone you like and try it for a few days - if it doesn't work out, exchange it for a different brand or frequency phone.
Be prepared to invest some time finding the best phone for your situation. A bad phone is a constant annoyance - life is just too short for that.
Mr Ritter, first let me commend you on your quick, open and frank response to this story. However, I have a couple of concerns with your reponse that I would like to ask you to address:
It sounds to me like you are simultaneously admitting that the problem was not handled to your normal standards, yet also admitting that if this story had not appeared on slashdot, there is no reason to expect that it would have been handled any differently. Care to comment?
You mention that "communication is now in an improved state". Could you elaborate on that? Does that mean you walked down to the lab and yelled "hey guys, you should talk to the customers more!", or does that mean that there has been a documented change in policy including safegaurds to ensure the policies are followed?
On a related note, one of the other posters indicates that in his/her experience, approx 1 in 10 VA boxes arrive DOA. Can you give us a more specific statistic, perhaps along with the average amount of time it takes to resolve these problems.
According to the CD-Recordable FAQ, a CDR which has been written to should last at least 75 years. Strangely, the FAQ suggests that CDR's which have not been written on only have a shelf life of 5-10 years.
Note that exposure to heat or direct sunlight can greatly reduce the life of the media. You haven't been leaving those CDR's on the front seat of your car have you?
The section of the FAQ which discusses longevity can be found here.
Slashdot Mirror
While spammers certainly don't worry about conforming with RFCs, it should be noted that rejecting email based on the DNS is a specific violation of the relevant RFC, RFC-5321, section 4.1.4, which states:
An SMTP server MAY verify that the domain name argument in the EHLO command actually corresponds to the IP address of the client. However, if the verification fails, the server MUST NOT refuse to accept a message on that basis.
That said, it is common practice to do this anyway. The reality is that you will not have reliable email delivery unless the hostname your server issues in the EHLO command resolves to the servers IP address and the IP address resolves back to that same name.
Try BZflag (www.bzflag.org).
Its open source and available for Linux/Windows/Mac and probably others.
Its conceptually simple, and therefore pretty quick to get started, but there are always new tactics/counter-tactics to learn.
Being open source, there are cheaters. But I've found this to be a minor problem. Most players seem to be honest and when you do encounter someone that appears to be cheating, just switch to a different server.
Its very sensitive to latency, so you will likely find that some servers work better for you than others. Each server has its own combination of rules/options, so you should try out several servers anyway, just to see what you like.
Its Free! Give it a try.
bzflag (www.bzflag.org) is open source, runs on windows and linux, and is small and efficient. It will run on almost any hardware if you use basic graphics. A good video card is required to get the best graphics, but it really doesn't affect gameplay.
It is basically a first person shooter, where each player is driving a tank and tries to shoot other players. But these are no ordinary tanks, they can take on special "powers" like the ability to jump, bounce shots off walls, aquire laser weapons, quided missles, etc.
There are many variations that can be introduced to make play easier or harder or just to change strategies. There is also a Capture the Flag variation.
Its good fun and downright addictive. And its free, so you've got nothing to lose - give it a try!
Oops!
You are, of course, correct.
But even with my "factor of 10" error, I think my conclusions are still valid. It still takes 5 years to pay for itself. I think the bottom line is still: The electricity costs (and therefore potential savings) for either type of lights is so low as to be negligable compared to the extra cost of the LEDs.
You shouldn't have to spend any time debugging the lights if you are replacing them every year (which was assumed in my calculation).
And remember, a burned out bulb is not the only source of failure - a broken wire or damaged connector can happen to both types of light sets.
The aesthetics are certainly debatable, but I don't find the difference in appearance between to the two lighting technologies to be interesting enough to debate.
As for the cost difference: Lets actually run some numbers:
Let's assume a string of traditional lights consumes 100 watts and a string of LEDs consumes nothing. (I think you would agree that both of these assumptions are more than fair to the LEDs).
If we energize the lights 8 hours per day for 30 days during each "holiday season", that is 240 hours per year that the lights are in use.
If we assume an electricity cost of US$0.10/kwh(which is typical around here, but varies widely depending where you live), that is an annual electricity cost of US$0.024. Lets just go ahead and round this up to 3 cents.
Let's further assume that the LED lights would last forever, but the traditional lights need to be replaced each year at a cost of US$1.50. We now have a total annual cost for the traditional lights of US$1.53 compared to the one time cost of US$20 for the LED lights.
That means it will take the LEDs approx 13 years to reach the break-even point against the traditional lights.
And remember, I made all my assumptions in the favor of the LEDs. Real LEDs do consume some power and real traditional lights don't need to be replaced every year and real LED lights will not last forever (the LEDs themselves might, but the wiring, etc will deteriote due to exposure to sun, weather, etc). So, in reality the break-even point is probably much more than 13 years.
If you just crave the LEDs, then go ahead and buy them, but don't try to claim that you are saving money by doing it.
Now I know that LED holiday lights may seem all hi-tech and geeky, but regular ones are so cheap and readily available, the LED ones just don't seem worth it.
The 80 light LED set linked to above costs about US$20 and come only in red. I can go to my local supermarket and get a regular 100 light set for $US1.47 in a variety of colors or multi-colored. For the cost of one LED string, I can buy 13 regular ones, and still have change left over. Thats 1300 lights vs 80 LEDs!! Sure the LEDs are more effiecient and sure, they will last longer, but not enough to come anywhere close to making up the cost difference.
I think a better "Ask Slashdot" would be: Gee, holiday lights are so darn cheap these days, what other uses can we find for them?" (and no, they won't run Linux, and no, you can't turn them into a web server....or can you?)
Is your friend being attacked because he/she is a sleazeball spammer? Be honest!
If that's the reason for the attacks, well, what can I tell you, your friend deserves everything he/she has coming to him/her. Come to think of it, probably deserves even worse.
You might as well ask "My friend keeps jumping in water and is still getting wet, what should he do?"
The database on an AS/400 is not a separate service - it is integrated into the operating system. All files are treated, more or less, as database tables. Any file (in OS/400 terms, a "Physical File") can be queried at any time.
To select files that were created within a specific timeframe, you would dump a list of files and their attributes in a given directory (IBM calls them "libraries") to a temporary file. This temporary file could then be queried as a database table, selecting files with specific attributes, such as a creation date within a given range.
For some reason, IBM has a different name for everything. Here are a few rough translations:
IPL = reboot (Initial Program Load)
DASD = disk space
Physical File = File/Database Table
Logical File = Index/View
Library = Directory
Most distros use very conservative settings for the IDE interfaces which will work with just about any old drives, but do not take advantage of more modern hardware. hdparm allows you to activate those advanced features.
There is a nice write-up about using hdparm here: http://www.oreillynet.com/pub/a/linux/2000/06/29/h dparm.html
Of course, all this only applies to Linux boxes.
ProxyConn's homepage brags that it "Works with all browsers / operating systems!".
However, if you dig a little deeper into their "Technology" page, you find that it works with any MS-Windows OS and only IE and Netscape browsers.
Never forget to read the fine print!!
tn5250 is what you need. It's been a couple years since I've used it, and back then it was functional, but a little quirky. I assume it is no worse now, and probably much better. At that time, at least, there were a several developers who were very active on the mailing list, often providing bug fixes the same day.
:)
It provides only 5250 terminal emulation, but not all the other stuff (file xfer, etc) that Client Access does.
They have a mailing list archive here. I suggest you browse through it to get an idea of how suitable it is for your needs. Of course, since its open source, you can always just download it and try it out.
(I've seen some suggestions to use 3270 emulators. While an AS/400 will grudgingly talk to a 3270, you loose a lot of the functionality that you are accustomed to from a 5250. Not a solution I reccommend)
A good write up about using hdparm to improve hd performance and the risks involved can be found here:
h dparm.html
...including some discussion of what those DMA modes are and their merits.
http://www.oreillynet.com/pub/a/linux/2000/06/29/
http://govschl.ndsu.nodak.edu/~achapwes/PICmicro/P S2/ps2.htm
http://www.nti1.com/ps2-prots.html
http://micro.new21.org/pic/html/tut_ps2/ps2.htm
I've had several Panasonic 900MHz phones in recent years and have been pleased with all of them. In my experience the digital spread spectrum models (Panansonic's buzzword for this is 'Gigarange') seem to offer a little more range and immunity to noise, and I would assume security from snooping. The difference in quality is not great, and if your budget is tight, I would not hesitate to go with the cheaper analog models.
In my opinion, their Gigarange models try to act too much like cell-phones with a deep and complex menu system that is just too awkward. Fortunately, you can just ignore all the 'gee whiz' features and use it as a good ol fashioned phone.
Consumers Reports did a test recently and concluded that there was no advantage to the 2.4GHz frequency over the 900MHz frequency. This has been my personal experience as well. I wouldn't pay any extra for a 2.4GHz phone. On the other hand, if you know you are already using one band (wireless network for example), that may be a good enough reason to get a phone that uses the other band just to reduce interference.
As it sounds like you have an electrically noisy environment, I think the best advice is to buy from a store will liberal return policies. Pick a phone you like and try it for a few days - if it doesn't work out, exchange it for a different brand or frequency phone.
Be prepared to invest some time finding the best phone for your situation. A bad phone is a constant annoyance - life is just too short for that.
Mr Ritter, first let me commend you on your quick, open and frank response to this story. However, I have a couple of concerns with your reponse that I would like to ask you to address:
It sounds to me like you are simultaneously admitting that the problem was not handled to your normal standards, yet also admitting that if this story had not appeared on slashdot, there is no reason to expect that it would have been handled any differently. Care to comment?
You mention that "communication is now in an improved state". Could you elaborate on that? Does that mean you walked down to the lab and yelled "hey guys, you should talk to the customers more!", or does that mean that there has been a documented change in policy including safegaurds to ensure the policies are followed?
On a related note, one of the other posters indicates that in his/her experience, approx 1 in 10 VA boxes arrive DOA. Can you give us a more specific statistic, perhaps along with the average amount of time it takes to resolve these problems.
Note that exposure to heat or direct sunlight can greatly reduce the life of the media. You haven't been leaving those CDR's on the front seat of your car have you?
The section of the FAQ which discusses longevity can be found here.
Here is a link to the page: http://www.mozillazine.org/sc reenshots/alookback.html
As mentioned, it is at the bottom of the page.
I fear we may be wandering off topic, but according to the CD Recordable FAQ (www.fadden.com/cdrfaq/):
Pressed CD's may last as little as 10-25 years.
CDR's once recorded should last at least 75 years, but strangely only have an unrecorded shelf life of 5 to 10 years.
So something like one out of five of the people around me are crazy.
Boy, that sure explains a lot!