Re: AH or ESP
IPsec as a whole is compliance mandatory for IPv6 although for new version of IPv6 Node requirements that came out recently I think they changed that to a 'SHOULD'. the reality is DON'T
Re: Multi-homed clients and BGP timers
Steve Bertrand wrote: My problem is the noticeable delay for switchover when the fibre happens to go down (God forbid). I would like to know if BGP timer adjustment is the way to adjust this, or if there is a better/different way. It's fair to say that the fibre doesn't 'flap'. Based on operational experience, if there is a problem with the fibre network, it's down for the count. Thanks to all for the great feedback. In summary, I've learnt: - Even though BFD would be a fantastic solution and would require only minimal changes (to my strict uRPF setup), it's a non-starter, as I don't fit all of the requirements that Ivan pointed out - fast-external-fallover is already enabled by default, but in order for this to be effective, the interface has to physically go into down state. In my case, although not impossible, it is extremely unlikely - adjusting BGP timers is the best option given it's really the only one left. Although I generally try to keep consistency among all equipment (if I set the timers at one end, I would set them the same at the other). Iljitsch recommended to leave the CPE end alone, so if something bad happens, access to the CPE would not be necessary to revert the change - I'm going to set the timers to 5/16. I like the idea of the extra second on top of being divisible by three. That will ensure that at least three keepalives have a chance to make it before the session hold timer is reached Cheers! Steve smime.p7s Description: S/MIME Cryptographic Signature
The adventures of Team ARIN
Semi-Off-Topic here, I know, but it might help Network Operators to explain certain misguided people and thus lower noise and raise signal in various places. https://www.arin.net/knowledge/comic.html Short short synopsis: comic about how ARIN handles certain things and what ARIN does etc. Greets, Jeroen -- Currently published issues: Issue 1 - The Beginning of Team ARIN - Synopsis: In issue 1, learn how Team ARIN was founded with the assistance of Jon Postel. See how active participation by the entire Internet community is key to Team ARIN's success as it endeavors to facilitate the open and transparent, bottom-up policy development processes. Issue 2 - FUD for Thought - Synopsis: In issue 2, Team ARIN embarks on a mission to raise awareness about the issue of depletion of the available pool of IPv4 addresses and encounters a new enemy -- Agent FUD. Working for the Bad Idea Force, FUD is busy trying to spread fear, uncertainty, and doubt about IPv4 address depletion. Using newly acquired technology, Team ARIN combines forces to help combat this new enemy of the open and transparent principles the Internet is based on, and in doing so creates something more than even they expected! Issue 3 - FUD 2.0 - Return of the FUD Factor! - Synposis: Issue 3 begins with Team ARIN flying back from a conference when they are alerted to a new problem and an old enemy. Agent FUD has returned and this time he's seeking to undermine the Internet community's migration to IPv6. Read the issue to find out how Team ARIN saves the day and how you can help! (s/synposis/synopsis/ by me, that typo is still on the original site, rest of content all by ARIN, nothing I can do about, thus don't complain to me ;) signature.asc Description: OpenPGP digital signature
[NANOG-announce] NANOG46 reminders
Hi Folks: One Last set of meeting reminders!! If you have not yet made your hotel reservations, you might want to consider doing so as the NANOG hotel room rate ends on Friday, May 29. Make sure to complete your NANOG registration soon, you do not want to miss out on an excellent program and opportunity to catch up in person with members of the NANOG community. On Monday, June 8 the registration late fee goes into effect. Lastly, do not forget to get those lighting talk ideas submitted! Look forward to seeing everyone in sunny Philly. Sincerely, Merit, NANOG Support Team ___ NANOG-announce mailing list nanog-annou...@nanog.org http://mailman.nanog.org/mailman/listinfo/nanog-announce
OT: ARIN Information
On May 26, 2009, at 11:14 AM, Jeroen Massar wrote: Semi-Off-Topic here, I know, but it might help Network Operators to explain certain misguided people and thus lower noise and raise signal in various places. Another resource is the recent slide deck released for community use: https://www.arin.net/announcements/2009/20090508_slides.html People who have further need for education or information materials for ARIN and IPv4/IPv6 address issues are encouraged to follow up on the arin-disc...@arin.net mailing list. Thanks! /John John Curran Acting President and CEO ARIN
MX Record Theories
Hello all, First, I hope this is not off-topic for NANOG, please be gentle with me as this is my first post. I would be most interested to hear NANOG theories on the variety of MX record practices out there, namely, how come there seem to be so many ways employed to achieve the same goal ? Do you have experience in more than one of these methods and which do you favour ? To illustrate my question : (1) If you query the MX records for, Hotmail or AOL you will receive 4 equal weight MX records, each of the MX records having a round-robin set of IPs. e.g. hotmail.com.2706INMX5 mx4.hotmail.com. hotmail.com.2706INMX5 mx1.hotmail.com. hotmail.com.2706INMX5 mx2.hotmail.com. hotmail.com.2706INMX5 mx3.hotmail.com. -and- mx3.hotmail.com.1926INA65.xxx mx3.hotmail.com.1926INA65.xxx mx3.hotmail.com.1926INA65.xxx etc.etc. (2) Alternatively, some people, particularly the ones that use hosted filtering, tend to have one MX record, which as multiple round robin IPs. e.g. microsoft.com.780INMX10 mail.global.frontbridge.com. -and- mail.global.frontbridge.com. 1728 INA65.xxx mail.global.frontbridge.com. 1728 INA207.xxx etc. etc. (3) And others simply have a more traditional setup using multiple MX records and only one IP per MX record with no round robin apple.com.931INMX10 mail-in14.apple.com. apple.com.931INMX20 mail-in3.apple.com. apple.com.931INMX20 eg-mail-in2.apple.com. etc.etc. So what's the big deal ? Please note I'm not asking which is better ... I am just curious and interested to hear your professional opinions and experiences. Personally, I favour the simple option 3, multiple MX records. Thanks y'all.
Re: MX Record Theories
I don't think there is no real answer for your question. It depends on each company's business objective, the cost, network topology, and their policy. MX record is the the mechanism for mail delivery procotol. It doesn't dictate how to implement. Depending on mail volume, and network policy, you can implement actual mail servers within DNS/SMTP protocol. There are multiple ways to get things done. Depending on budget, business objective, network resource/policy, you can choose the way that fits to your need. It is same as Microsoft Windows operating system. Microsoft release the Windows, but it doesn't say you have to run it as cluster or not. Depending on your need, and your own analysis/decision, you can run whatever you like. Alex gb10hkzo-na...@yahoo.co.uk wrote: Hello all, First, I hope this is not off-topic for NANOG, please be gentle with me as this is my first post. I would be most interested to hear NANOG theories on the variety of MX record practices out there, namely, how come there seem to be so many ways employed to achieve the same goal ? Do you have experience in more than one of these methods and which do you favour ? To illustrate my question : (1) If you query the MX records for, Hotmail or AOL you will receive 4 equal weight MX records, each of the MX records having a round-robin set of IPs. e.g. hotmail.com.2706INMX5 mx4.hotmail.com. hotmail.com.2706INMX5 mx1.hotmail.com. hotmail.com.2706INMX5 mx2.hotmail.com. hotmail.com.2706INMX5 mx3.hotmail.com. -and- mx3.hotmail.com.1926INA65.xxx mx3.hotmail.com.1926INA65.xxx mx3.hotmail.com.1926INA65.xxx etc.etc. (2) Alternatively, some people, particularly the ones that use hosted filtering, tend to have one MX record, which as multiple round robin IPs. e.g. microsoft.com.780INMX10 mail.global.frontbridge.com. -and- mail.global.frontbridge.com. 1728 INA65.xxx mail.global.frontbridge.com. 1728 INA207.xxx etc. etc. (3) And others simply have a more traditional setup using multiple MX records and only one IP per MX record with no round robin apple.com.931INMX10 mail-in14.apple.com. apple.com.931INMX20 mail-in3.apple.com. apple.com.931INMX20 eg-mail-in2.apple.com. etc.etc. So what's the big deal ? Please note I'm not asking which is better ... I am just curious and interested to hear your professional opinions and experiences. Personally, I favour the simple option 3, multiple MX records. Thanks y'all.
Re: MX Record Theories
On Tue, 26 May 2009 11:03:59 PDT, gb10hkzo-na...@yahoo.co.uk said: would be most interested to hear NANOG theories on the variety of MX record practices out there, namely, how come there seem to be so many ways employed to achieve the same goal ? The trick here is that it isn't always *exactly* the same goal. There's multiple mail system architectures and design philosophies. One often overlooked but very important design point for the *large* providers: % dig aol.com mx ;; ANSWER SECTION: aol.com.2805IN MX 15 mailin-01.mx.aol.com. aol.com.2805IN MX 15 mailin-02.mx.aol.com. ... ;; WHEN: Tue May 26 14:40:41 2009 ;; MSG SIZE rcvd: 507 That 507 is critically important if you want to receive e-mail from sites with fascist firewalls that block EDNS0 and/or TCP/53. 5 bytes left. ;) pgpVa3ctskTZ8.pgp Description: PGP signature
Re: MX Record Theories
On Tue, May 26, 2009 at 2:03 PM, gb10hkzo-na...@yahoo.co.uk wrote: I would be most interested to hear NANOG theories on the variety of MX record practices out there, namely, how come there seem to be so many ways employed to achieve the same goal ? Do you have experience in more than one of these methods and which do you favour ? apple.com.931INMX10 mail-in14.apple.com. apple.com.931INMX20 mail-in3.apple.com. apple.com.931INMX20 eg-mail-in2.apple.com. etc.etc. Use this when only the front server is fully capable of processing the mail into the domain. The other servers will have to hold some or all of the mail until the first server or its cold spare returns to service. Or perhaps the secondary servers are fully capable but undesirable for some other reason, such as slower hardware or older versions of the software. microsoft.com.780INMX10 mail.global.frontbridge.com. -and- mail.global.frontbridge.com. 1728 INA65.xxx mail.global.frontbridge.com. 1728 INA207.xxx Use this when you have multiple front-end servers any of which is fully capable of handling all messages entering the system. Free load balancer built into the protocol. hotmail.com. 2706 IN MX 5 mx4.hotmail.com. hotmail.com. 2706 IN MX 5 mx1.hotmail.com. hotmail.com. 2706 IN MX 5 mx2.hotmail.com. hotmail.com. 2706 IN MX 5 mx3.hotmail.com. -and- mx3.hotmail.com. 1926 IN A 65.xxx mx3.hotmail.com. 1926 IN A 65.xxx mx3.hotmail.com. 1926 IN A 65.xxx Use this when you have a large number of front-end servers fully capable of handling messages entering the system -and- you're somewhat clueful. The difference is that you want the IP addresses of the servers to be included as additional information in the DNS response. If you have a large number of addresses, they're all under the same name and including them all would make the DNS response packet larger than a few hundred bytes, the server will drop the additional information, requiring a second DNS lookup and possibly a third TCP-based DNS lookup in order to get it. By splitting them up, the DNS server will pack as many sets of addresses as it can into the original response packet. Regards, Bill Herrin -- William D. Herrin her...@dirtside.com b...@herrin.us 3005 Crane Dr. .. Web: http://bill.herrin.us/ Falls Church, VA 22042-3004
PLNOG3 - 10-11.09.2009 - Call for Papers!
Hello,
Polish Network Operators Group (PLNOG)[1] will meet for the third
time ever on 10th and 11th of September 2009 in Cracow, Poland.
We would like to invite You all to submit your presentation proposal.
The plan for PLNOG 3rd is to have three tracks:
* Architectures and technologies - sessions covering networking
solutions, future of standards and the standarization process
for current technologies;
* Real-life deployments and best practices - sessions covering
first-hand experience with deployment of specific solutions,
products and solutions
* Content provider architecture and scalability - dedicated for
people interested in building backends for all kinds of
networking sites like portals, community sites and etc.
Additionally, we would like to invite You to suggest subjects for the
open discussion sessions that will take place before the main event
and after the keynotes. Last subjects revolved around IPv6 deployment
and lawful intercept issues from the government and practical point
of view.
The submissions will be discussed by the PLNOG board[2], so the dead
line for them is 25th of June, 2009. The full agenda with all
sessions will be published no later than to 10th of July, 2009.
CfP proposals should be sent to following e-mail:
andrzej.targosz {%} proidea.org.pl
with the prefix 'PLNOG3' in subject.
We would also like to invite all vendors to participate in
presentations - however, bear in mind please no vendor-oriented
sessions will be permitted, which means no sales, no marketing, only
pure technical stuff. The pointers to some specific design issues,
products or solutions are allowed if they follow approved presentation
flow and are relevant to subject covered.
Last but not least - if You want to sponsor PLNOG we'd be more than
happy to discuss this with You.
[1]. http://www.plnog.pl
[2]. http://plnog.pl/komiter-i-rada-nog/lang-pref/en/
--
Don't expect me to cry for all the | Łukasz Bromirski
reasons you had to die -- Kurt Cobain |http://lukasz.bromirski.net
Why choose 120 volts?
I have a pure curiosity question for the NANOG crowd here. If you run your facility/datacenter/cage/rack on 120 volts, why? I've been running my facility at 208 for years because I can get away with lower amperage circuits. I'm curious about the reasons for using high-amp 120 volt circuits to drive racks of equipment instead of low-amp 208 or 240 volt circuits. ~Seth
RE: Why choose 120 volts?
I have a pure curiosity question for the NANOG crowd here. If you run your facility/datacenter/cage/rack on 120 volts, why? Because we are stupid. I've been running my facility at 208 for years because I can get away with lower amperage circuits. I'm curious about the reasons for using high-amp 120 volt circuits to drive racks of equipment instead of low-amp 208 or 240 volt circuits. That makes you smarter than the average guy. But, if we were really smart, we'd run at least 277, or maybe 347. Countless amounts of money would be saved on losses (transformation), copper (smaller wire), and many other areas. Most of the stuff we all run is already insulated for these voltage levels. Even better would be all two pole 2 pole 480's or 2 pole 600's, then we wouldn't need neutrals.
RE: AH or ESP
Merike Kaeo wrote: ... ESP-Null came about when folks realized AH could not traverse NATs. Thus the absolute reason why people should promote AH to kill off the 66nat nonsense. Just because you can't use it for IPv4 is no reason to avoid using it for IPv6 now and let its momentum suppress the 66CGN walled garden mindset. Tony
Re: Why choose 120 volts?
From: Alex Rubenstein a...@corp.nac.net Date: Tue, 26 May 2009 15:43:20 -0400 I have a pure curiosity question for the NANOG crowd here. If you run your facility/datacenter/cage/rack on 120 volts, why? Because we are stupid. I've been running my facility at 208 for years because I can get away with lower amperage circuits. I'm curious about the reasons for using high-amp 120 volt circuits to drive racks of equipment instead of low-amp 208 or 240 volt circuits. That makes you smarter than the average guy. But, if we were really smart, we'd run at least 277, or maybe 347. Countless amounts of money would be saved on losses (transformation), copper (smaller wire), and many other areas. Most of the stuff we all run is already insulated for these voltage levels. Even better would be all two pole 2 pole 480's or 2 pole 600's, then we wouldn't need neutrals. Oh, yeah! Nothing sounds like more fun than working in a room full of 480 or 600 delta. I LIKE neutrals. (Sort of like I like continuing to have a functioning heart.) -- R. Kevin Oberman, Network Engineer Energy Sciences Network (ESnet) Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab) E-mail: ober...@es.net Phone: +1 510 486-8634 Key fingerprint:059B 2DDF 031C 9BA3 14A4 EADA 927D EBB3 987B 3751
RE: Why choose 120 volts?
Even better would be all two pole 2 pole 480's or 2 pole 600's, then we wouldn't need neutrals. Oh, yeah! Nothing sounds like more fun than working in a room full of 480 or 600 delta. I LIKE neutrals. (Sort of like I like continuing to have a functioning heart.) Nobody said delta.
Re: AH or ESP
On May 27, 2009, at 3:00 AM, Tony Hain wrote: Just because you can't use it for IPv4 is no reason to avoid using it for IPv6 now and let its momentum suppress the 66CGN walled garden mindset. I concur quite strongly with your views on this particular topic, but the CGN boat appears to've sailed, AFAICT. --- Roland Dobbins rdobb...@arbor.net // http://www.arbornetworks.com Unfortunately, inefficiency scales really well. -- Kevin Lawton
RE: Why choose 120 volts?
Oh, yeah! Nothing sounds like more fun than working in a room full of 480 or 600 delta. I LIKE neutrals. (Sort of like I like continuing to have a functioning heart.) Nobody said delta. If you just run 7200vac into your 1u chinese made peecee servers, then you can eliminate the space use of the step-down transformer in the mechanical room.
RE: Why choose 120 volts?
Why stop there? Grab a 20,000 volt feeder and create a Tesla datacenter. Think of all the copper you will save... -Original Message- From: telmn...@757.org [mailto:telmn...@757.org] Sent: Tuesday, May 26, 2009 3:16 PM Cc: nanog@nanog.org Subject: RE: Why choose 120 volts? Oh, yeah! Nothing sounds like more fun than working in a room full of 480 or 600 delta. I LIKE neutrals. (Sort of like I like continuing to have a functioning heart.) Nobody said delta. If you just run 7200vac into your 1u chinese made peecee servers, then you can eliminate the space use of the step-down transformer in the mechanical room.
Re: MX Record Theories
Hi, I thought i'd give you a quick response (and welcome to NANOG) :). Thanks. I can't believe that I've already received three very interesting responses in just over an hour ! I've been quietly lurking on NANOG for a while, just plucked up the courage to post . and might now even find a bit more courage to attempt to contribute to some threads ! Glad to see the community spirit still exists ! Keep the replies coming if there are any still on their way . :) Tim P.S. Valdis Kletnieks . I've got the feeling that this That 507 is critically important if it's true, might potentially explain a few intermittent unexplicable issues we've been seeing at some sites time for some research me thinks :)
Re: Why choose 120 volts?
Doesn't even need non-standard servers - just wire them all in series. On Tue, May 26, 2009 at 03:23:46PM -0500, Kurt Anderson wrote: Why stop there? Grab a 20,000 volt feeder and create a Tesla datacenter. Think of all the copper you will save...
Re: Why choose 120 volts?
On May 26, 2009, at 3:29 PM, Barney Wolff wrote: On Tue, May 26, 2009 at 03:23:46PM -0500, Kurt Anderson wrote: Why stop there? Grab a 20,000 volt feeder and create a Tesla datacenter. Think of all the copper you will save... Oh, c'mon people! We need to all think green here too. All you need is to locate it in the right spot on the planet and set up a big lightning rod. The first sustainable energy datacenter with no emissions! -Andy
Re: Why choose 120 volts?
So when one server fails, all the rest fail too? Sorting out holiday lighting is bad enough could you imagine having to go through rack after rack finding the one burned out server? On Tue, 2009-05-26 at 16:29 -0400, Barney Wolff wrote: Doesn't even need non-standard servers - just wire them all in series. On Tue, May 26, 2009 at 03:23:46PM -0500, Kurt Anderson wrote: Why stop there? Grab a 20,000 volt feeder and create a Tesla datacenter. Think of all the copper you will save... -- Prediction is very difficult, especially about the future. Niels Bohr -- Ray Sanders Linux Administrator Village Voice Media Office: 602-744-6547 Cell: 602-300-4344
RE: Why choose 120 volts?
It will be like at Christmas time, trying to find the bad bulb. -Original Message- From: Barney Wolff [mailto:bar...@databus.com] Sent: Tuesday, May 26, 2009 4:29 PM To: nanog@nanog.org Subject: Re: Why choose 120 volts? Doesn't even need non-standard servers - just wire them all in series. On Tue, May 26, 2009 at 03:23:46PM -0500, Kurt Anderson wrote: Why stop there? Grab a 20,000 volt feeder and create a Tesla datacenter. Think of all the copper you will save...
Re: Why choose 120 volts?
I have a pure curiosity question for the NANOG crowd here. If you run your facility/datacenter/cage/rack on 120 volts, why? I've been running my facility at 208 for years because I can get away with lower amperage circuits. I'm curious about the reasons for using high-amp 120 volt circuits to drive racks of equipment instead of low-amp 208 or 240 volt circuits. 208 isn't all that great. On one hand, a 20A 208V circuit is vaguely more convenient than a 30A 120V circuit because it is delivering a bit more power to the rack (3328 vs 2880), and it's likely to work with a lot of modern equipment containing autoranging power supplies. On the flip side, with 120, you don't have to have odd cords, and it is somewhat easier to right-size power for a rack (20A, 30A, 2x20A), so for an average rack that isn't crammed with high power webhosting 1U's (etc), a customer might actually find that the ability to right- size the power feed is more flexible with 120V. And I don't like not having anywhere to plug in my power screwdriver's recharger... I suppose I should see if I can find someplace that has a transformer of an appropriate size, or does anyone already have the part number for something that can provide a few hunderd milliamps of 120V from 208? :-) ... JG -- Joe Greco - sol.net Network Services - Milwaukee, WI - http://www.sol.net We call it the 'one bite at the apple' rule. Give me one chance [and] then I won't contact you again. - Direct Marketing Ass'n position on e-mail spam(CNN) With 24 million small businesses in the US alone, that's way too many apples.
Re: Why choose 120 volts?
It will be like at Christmas time, trying to find the bad bulb. This sounds like an opportunity for you guys to find that special tool everyone needs, and sell it to all of us. ;-) (Dave's with Stayonline, and if you haven't been to his company's web site, they're full of wonderful odds and ends ... at a bit of a mark- up.) ... JG -- Joe Greco - sol.net Network Services - Milwaukee, WI - http://www.sol.net We call it the 'one bite at the apple' rule. Give me one chance [and] then I won't contact you again. - Direct Marketing Ass'n position on e-mail spam(CNN) With 24 million small businesses in the US alone, that's way too many apples.
Re: Why choose 120 volts?
On May 26, 2009, at 1:34 PM, Ray Sanders wrote: So when one server fails, all the rest fail too? Sorting out holiday lighting is bad enough could you imagine having to go through rack after rack finding the one burned out server? Who has to imagine? Some of us remember thinnet (10base2). Owen
RE: Why choose 120 volts?
Our power is handed to us at 480v. We then deliver it to the customer at whatever they need. The nice thing about 120v is that everything uses it. No odd cords (as mentioned before) or expensive PDUs. I've had a lot of people suggest that running our servers at 240v would save us money because we'd use less amps. Last time I looked at my bill I was being billed by the kWh, not amp and 240v at half the amps is still the same wattage. I've been told this so many times though that I'm starting to doubt myself. If anyone can present a reason for me to switch to 240v I'd like to hear it. Aaron -Original Message- From: Seth Mattinen [mailto:se...@rollernet.us] Sent: Tuesday, May 26, 2009 2:39 PM To: nanog@nanog.org Subject: Why choose 120 volts? I have a pure curiosity question for the NANOG crowd here. If you run your facility/datacenter/cage/rack on 120 volts, why? I've been running my facility at 208 for years because I can get away with lower amperage circuits. I'm curious about the reasons for using high-amp 120 volt circuits to drive racks of equipment instead of low-amp 208 or 240 volt circuits. ~Seth
Re: Why choose 120 volts?
Also, adding followings. 5) availability from local power provider(s) 6) local regulation such as fire department safety rules... 7) for your own safety... (120V may not kill people, but 240V can do...) If you want better, why not just have everything to DC power ? Something like 48V... Alex Wayne E. Bouchard wrote: 1) Equipment used to not be dual voltage 2) For smaller scale, 120V UPS and distribution equipment is usually cheaper 3) 120V embedded itself into operations as a result. 4) We're all lazy and hate change. On Tue, May 26, 2009 at 12:39:10PM -0700, Seth Mattinen wrote: I have a pure curiosity question for the NANOG crowd here. If you run your facility/datacenter/cage/rack on 120 volts, why? I've been running my facility at 208 for years because I can get away with lower amperage circuits. I'm curious about the reasons for using high-amp 120 volt circuits to drive racks of equipment instead of low-amp 208 or 240 volt circuits. ~Seth --- Wayne Bouchard w...@typo.org Network Dude http://www.typo.org/~web/
Re: Why choose 120 volts?
Ugh, please don't remind me of the hell that was coax. On Tue, 2009-05-26 at 13:45 -0700, Owen DeLong wrote: On May 26, 2009, at 1:34 PM, Ray Sanders wrote: So when one server fails, all the rest fail too? Sorting out holiday lighting is bad enough could you imagine having to go through rack after rack finding the one burned out server? Who has to imagine? Some of us remember thinnet (10base2). Owen -- Prediction is very difficult, especially about the future. Niels Bohr -- Ray Sanders Linux Administrator Village Voice Media Office: 602-744-6547 Cell: 602-300-4344
Re: AH or ESP
Tony Hain wrote: Merike Kaeo wrote: ... ESP-Null came about when folks realized AH could not traverse NATs. Thus the absolute reason why people should promote AH to kill off the 66nat nonsense. Just because you can't use it for IPv4 is no reason to avoid using it for IPv6 now and let its momentum suppress the 66CGN walled garden mindset. That should make for a fascinating discussion. You should use AH. Why? So you can't use NAT. Any other reason? ... No. Great. I'll get right on that. The delusion that network operators can successfully use unhelpful protocols and/or smoke and mirrors to force idealist network design on others needs to end. People use new protocols because they are better. If the benefit of moving to a new protocol does not outweigh the pain of moving to it, people don't use it. That's why the OSI protocols did not kill IP like they were supposed to in the 90s, it is why the largely forgotten mandated move from Windows to secure OSes (ie, Unix) for all government employees never happened, and it is why IPv6 is sputtering. If people want to use NAT, they are going to use NAT. They may stop using it if the widespread adoption of peer to peer protocols means they are missing out on things other people are doing. They are not going to stop using NAT to use a protocol maliciously designed to break it; they will just wait, patiently and nearly always successfully, for somebody to come out with a version that has no such malice. They are certainly not going to stop using NAT because somebody tells them they should use a security protocol that does not secure anything worth securing. BitTorrent is a better anti-NAT tool than AH ever will be. More carrot, less stick. -Dave
Re: Why choose 120 volts?
I still have a couple of Ethernet cards for 10Base2, and cables. ^.^ Yes, if someone unplug or it is loosen in the middle/end, it will be fun. I guess it's going to be another bagel/coffee time except network support people. Alex Ray Sanders wrote: Ugh, please don't remind me of the hell that was coax. On Tue, 2009-05-26 at 13:45 -0700, Owen DeLong wrote: On May 26, 2009, at 1:34 PM, Ray Sanders wrote: So when one server fails, all the rest fail too? Sorting out holiday lighting is bad enough could you imagine having to go through rack after rack finding the one burned out server? Who has to imagine? Some of us remember thinnet (10base2). Owen
RE: Why choose 120 volts? When DC will do
What is all this talk about AC. Real data centers use DC. John (ISDN) Lee From: Seth Mattinen [se...@rollernet.us] Sent: Tuesday, May 26, 2009 3:39 PM To: nanog@nanog.org Subject: Why choose 120 volts? I have a pure curiosity question for the NANOG crowd here. If you run your facility/datacenter/cage/rack on 120 volts, why? I've been running my facility at 208 for years because I can get away with lower amperage circuits. I'm curious about the reasons for using high-amp 120 volt circuits to drive racks of equipment instead of low-amp 208 or 240 volt circuits. ~Seth
Re: Why choose 120 volts? When DC will do
I second that! - Original Message - From: John Lee j...@internetassociatesllc.com To: Seth Mattinen se...@rollernet.us; nanog@nanog.org nanog@nanog.org Sent: Tue May 26 12:56:42 2009 Subject: RE: Why choose 120 volts? When DC will do What is all this talk about AC. Real data centers use DC. John (ISDN) Lee From: Seth Mattinen [se...@rollernet.us] Sent: Tuesday, May 26, 2009 3:39 PM To: nanog@nanog.org Subject: Why choose 120 volts? I have a pure curiosity question for the NANOG crowd here. If you run your facility/datacenter/cage/rack on 120 volts, why? I've been running my facility at 208 for years because I can get away with lower amperage circuits. I'm curious about the reasons for using high-amp 120 volt circuits to drive racks of equipment instead of low-amp 208 or 240 volt circuits. ~Seth
Re: Why choose 120 volts?
Aaron Wendel wrote: Our power is handed to us at 480v. We then deliver it to the customer at whatever they need. The nice thing about 120v is that everything uses it. No odd cords (as mentioned before) or expensive PDUs. I've had a lot of people suggest that running our servers at 240v would save us money because we'd use less amps. Last time I looked at my bill I was being billed by the kWh, not amp and 240v at half the amps is still the same wattage. I've been told this so many times though that I'm starting to doubt myself. If anyone can present a reason for me to switch to 240v I'd like to hear it. Some servers (HP/Compaq comes to mind) and Cisco switches have limitations in terms of performance and/or capacity on 120v circuits. Yes, it all gets crunched down to 5VDC and similar low voltages in the power supply. The limitation is likely due to the gauge of wire used and copper losses in the input circuitry. Higher current connectors and switches, larger copper conductors, etc. are costly. If you have an application that needs that kind of power, higher voltages make sense. This is just as true if the application is a server as it is if it's an electric stove or clothes dryer. Most of the rest of the world has 240v as conventional domestic power, and most server rooms or datacenters supporting 2KVA single devices have 208 or 240v available, so it makes sense for manufacturers of high-power gear to save the money on copper and connectors and insist on higher input voltages for full spec output. Yes, it would be nice to be able to plug in your laptop charger, etc. And the voltage on that charger is likely compatible with anything from 100 to 240V. Wiring a NEMA 5-15 with 208V is just wrong, though. I have an IEC male to NEMA 5-15 female pigtail (old-school monitor cord) with a big sticker saying 208V - Be very careful what you plug in here for just that purpose. -- Jay Hennigan - CCIE #7880 - Network Engineering - j...@impulse.net Impulse Internet Service - http://www.impulse.net/ Your local telephone and internet company - 805 884-6323 - WB6RDV
Re: Why choose 120 volts?
Last time I looked at my bill I was being billed by the kWh, not amp and 240v at half the amps is still the same wattage. Losses are I^2*R, so double the voltage, half the current and experience a quarter of the loss... Janet Plato
Re: Why choose 120 volts?
Yes - think of all the nasty partial failure cases that can be eliminated - each entire datacenter is either up or down. Much simpler! Getting back to reality, I've watched more than one electrician do a two-finger liveness test on a 120v circuit, and done it myself. 240v HURTS, and I've not seen a pro finger it deliberately. But I haven't actually asked. On Tue, May 26, 2009 at 01:34:41PM -0700, Ray Sanders wrote: So when one server fails, all the rest fail too? On Tue, 2009-05-26 at 16:29 -0400, Barney Wolff wrote: Doesn't even need non-standard servers - just wire them all in series. On Tue, May 26, 2009 at 03:23:46PM -0500, Kurt Anderson wrote: Why stop there? Grab a 20,000 volt feeder and create a Tesla datacenter. -- Barney Wolff I never met a computer I didn't like.
Re: Why choose 120 volts?
In a message written on Tue, May 26, 2009 at 12:39:10PM -0700, Seth Mattinen wrote: I have a pure curiosity question for the NANOG crowd here. If you run your facility/datacenter/cage/rack on 120 volts, why? If folks are making their own choices, mainly for historical and convenience reasons. If folks are building data centers for others, it's that customers demand 120V power in many instances, for some good, and many bad reasons. However, for all the talk of power loss that's not the real issue. The loss due to wire or amperage is a very small part of the equation. While this paper is very much vendor produced, it's a good high level summary none the less: http://www.apcmedia.com/salestools/NRAN-6CN8PK_R0_EN.pdf Note that in a 600Kw installation power loss is reduced from 8,894 W to 845 W, a savings of 1.3%. Note that they have included the savings from additional cooling in that figure. Even at 1.3%, if you looked at the cost of rewiring an existing data center based on that figure you'd be nutty; return on investment would be forever. But what you'll find in the paper is that the change allows you to re-architect the power plant in a way that saves you money on PDU's, transformers, and other stuff. Thus this makes the most sense to consider in a green field deployment. Thus, to reframe your question, in your existing, already built out data center is it worth replacing 120V circuits with 208V/230V ones to save power? No. Savings is likely well under 1% in that situation, and time you add in the capital cost to do the work it makes no sense. In your green field, new data center, does it make sense to look at power from an entirely new point of view? Quite possibly. -- Leo Bicknell - bickn...@ufp.org - CCIE 3440 PGP keys at http://www.ufp.org/~bicknell/ pgpSoHlvGJbAb.pgp Description: PGP signature
Re: Why choose 120 volts?
Joe Greco wrote: 208 isn't all that great. On one hand, a 20A 208V circuit is vaguely more convenient than a 30A 120V circuit because it is delivering a bit more power to the rack (3328 vs 2880), and it's likely to work with a lot of modern equipment containing autoranging power supplies. On the flip side, with 120, you don't have to have odd cords, and it is somewhat easier to right-size power for a rack (20A, 30A, 2x20A), so for an average rack that isn't crammed with high power webhosting 1U's (etc), a customer might actually find that the ability to right- size the power feed is more flexible with 120V. I don't find it makes much difference, really. People are used to working with 120 only because that's how we roll in the USA; scary high voltage is for the oven and dryer. I like odd cords; it makes the protected power stuff blazingly obvious and slightly harder to plug dumb things into a UPS branch circuit because hey, a plug is a plug, right? And I don't like not having anywhere to plug in my power screwdriver's recharger... I suppose I should see if I can find someplace that has a transformer of an appropriate size, or does anyone already have the part number for something that can provide a few hunderd milliamps of 120V from 208? :-) True, you do lose the convenience outlet factor. I made up for it by placing standard 120V outlets (utility/generator only) along the walls. It works out because I hate those stupid wall warts with a passion. I go out of my way to buy products that come with a corded transformer, especially if it has a C14 connector on it. If you're adept at electrical stuff you can always get a small transformer, put it in a box, stick a C14 on the high side and a 5-15 on the low side. Nothing fancy required. ~Seth
Re: Why choose 120 volts?
On May 26, 2009, at 4:23 PM, Kurt Anderson wrote: Why stop there? Grab a 20,000 volt feeder and create a Tesla datacenter. Think of all the copper you will save... http://video.google.com/videoplay?docid=4468957986746104671 - Jared
Colo on the West Coast
Hi, I'm looking for a colo provider somewhere on the west coast, preferably somewhere close to one of the peering exchanges. A virtual machine will do. I want to use it to run a small performance monitoring box (traceroutes, pings, etc). I also would like to get a full bgp feed into it so I can monitor bgp as well. Who do you think would be the best one to do it with? (answers can be off-list) kind regards Pshem
Re: Why choose 120 volts?
Jay Hennigan wrote: Most of the rest of the world has 240v as conventional domestic power, and most server rooms or datacenters supporting 2KVA single devices have 208 or 240v available, so it makes sense for manufacturers of high-power gear to save the money on copper and connectors and insist on higher input voltages for full spec output. We're all 230vac here in Oz (it's a compromise between our old 240v standard and the Euro 220v one). In Oz we basically have a single style of outlet for AC for low amps and a couple of ones for higher amps. The higher powered PSUs are much easier to deal with on that - everytime we get ready to commission a new router etc for the US or Japan we look in amazement at the endless list of NEMA plugs and voltage options and different kinds of APC power gear we need to do everything. It kind of freaks me out - locking, not locking etc. Admittedly I find the standard 2 pin US style power connector somewhat wobbly and scary - ours seems to lock in much better. Since we get the same gear as North America mostly almost all of it copes with 90v to 240v AC 50/60hz. It's rare these days to find things without switching PSUs. It's worth noting that despite higher voltages here there aren't more deaths or injuries - but maybe it's because people take it more seriously. Admittedly no one I know is nuts enough to use body parts for liveness testing. MMC Yes, it would be nice to be able to plug in your laptop charger, etc. And the voltage on that charger is likely compatible with anything from 100 to 240V. Wiring a NEMA 5-15 with 208V is just wrong, though. I have an IEC male to NEMA 5-15 female pigtail (old-school monitor cord) with a big sticker saying 208V - Be very careful what you plug in here for just that purpose. -- Jay Hennigan - CCIE #7880 - Network Engineering - j...@impulse.net Impulse Internet Service - http://www.impulse.net/ Your local telephone and internet company - 805 884-6323 - WB6RDV
RE: Colo on the West Coast
Pshem, Datapipe and hurricane electric come to mind. Mobile email powered by the force... Original Message From: Pshem Kowalczyk pshe...@gmail.com Date: 5/26/09 4:03 pm To: nanog@nanog.org nanog@nanog.org Subj: Colo on the West Coast Hi, I'm looking for a colo provider somewhere on the west coast, preferably somewhere close to one of the peering exchanges. A virtual machine will do. I want to use it to run a small performance monitoring box (traceroutes, pings, etc). I also would like to get a full bgp feed into it so I can monitor bgp as well. Who do you think would be the best one to do it with? (answers can be off-list) kind regards Pshem
Re: Why choose 120 volts?
On Tue, May 26, 2009 at 03:39:30PM -0500, Joe Greco wrote: And I don't like not having anywhere to plug in my power screwdriver's recharger... I suppose I should see if I can find someplace that has a transformer of an appropriate size, or does anyone already have the part number for something that can provide a few hunderd milliamps of 120V from 208? :-) We always seem to have an odd device or three that needs 120V, like a wallwart for an external modem or LCD KVM console, or some legacy specialized gear (CBORD comes to mind). For those we have been providing a single circuit/PDU in the room that runs at 120V and running extension cords as necessary. Everything else is 208V.
Re: AH or ESP
The delusion that network operators can successfully use unhelpful protocols and/or smoke and mirrors to force idealist network design on others needs to end. People use new protocols because they are better. If the benefit of moving to a new protocol does not outweigh the pain of moving to it, people don't use it. That's why the OSI protocols did not kill IP like they were supposed to in the 90s, it is why the largely forgotten mandated move from Windows to secure OSes (ie, Unix) for all government employees never happened, and it is why IPv6 is sputtering. If people want to use NAT, they are going to use NAT. They may stop using it if the widespread adoption of peer to peer protocols means they are missing out on things other people are doing. They are not going to stop using NAT to use a protocol maliciously designed to break it; they will just wait, patiently and nearly always successfully, for somebody to come out with a version that has no such malice. They are certainly not going to stop using NAT because somebody tells them they should use a security protocol that does not secure anything worth securing. BitTorrent is a better anti-NAT tool than AH ever will be. More carrot, less stick. I agree. Folks are going to use ESP-NULL if they really want Integrity Protection .. -Dave
Re: MX Record Theories
In message 163001.1243364...@turing-police.cc.vt.edu, valdis.kletni...@vt.edu writes: --==_Exmh_1243364471_3846P Content-Type: text/plain; charset=us-ascii On Tue, 26 May 2009 11:03:59 PDT, gb10hkzo-na...@yahoo.co.uk said: would be most interested to hear NANOG theories on the variety of MX record practices out there, namely, how come there seem to be so many ways employed to achieve the same goal ? The trick here is that it isn't always *exactly* the same goal. There's multiple mail system architectures and design philosophies. One often overlooked but very important design point for the *large* provider s: % dig aol.com mx ;; ANSWER SECTION: aol.com.2805IN MX 15 mailin-01.mx.aol.com. aol.com.2805IN MX 15 mailin-02.mx.aol.com. ... ;; WHEN: Tue May 26 14:40:41 2009 ;; MSG SIZE rcvd: 507 That 507 is critically important if you want to receive e-mail from sites with fascist firewalls that block EDNS0 and/or TCP/53. 5 bytes left. ;) Actually TCP/53 out is almost always allowed. Too many things break if you block TCP/53 out. Similarly TCP to recursive servers is almost always allowed because blocking it breaks too many things. Recursive nameservers generally deal with stupid firewalls by adjusting how they make their queries. ed...@4096 - ed...@512 - plain DNS. Stub resolvers generally don't do EDNS so the are not impacted by stupid firewalls. This will changes as DNSSEC processing moves into the application. A EDNS referral from the root servers to the COM servers already exceeded 512 bytes. The world hasn't fallen over. That's dealt with that myth. Mark -- Mark Andrews, ISC 1 Seymour St., Dundas Valley, NSW 2117, Australia PHONE: +61 2 9871 4742 INTERNET: mark_andr...@isc.org
Re: Why choose 120 volts?
Once upon a time, Joe Greco jgr...@ns.sol.net said: And I don't like not having anywhere to plug in my power screwdriver's recharger... I suppose I should see if I can find someplace that has a transformer of an appropriate size, or does anyone already have the part number for something that can provide a few hunderd milliamps of 120V from 208? :-) Isn't 208V usually provided as a connection across two phases of a 3 phase circuit? In that case, you get 120V by going between one phase and neutral (no transformer required). You need a NEMA 14 (4 wire) connector to get two phases, neutral, and ground (provides 1 208V circuit and/or 2 120V circuits) or a NEMA L21 (5 wire) connector to get all three phases, neutral, and ground (provides 3 208V circuits and/or 3 120V circuits). -- Chris Adams cmad...@hiwaay.net Systems and Network Administrator - HiWAAY Internet Services I don't speak for anybody but myself - that's enough trouble.
RE: Why choose 120 volts?
Yes, you are correct Chris. The loss from getting 240 from two legs is due to the fact that it is at 120 instead of 180 deg's. -Original Message- From: Chris Adams [mailto:cmad...@hiwaay.net] Sent: Tuesday, May 26, 2009 7:52 PM To: Joe Greco Cc: nanog@nanog.org Subject: Re: Why choose 120 volts? Once upon a time, Joe Greco jgr...@ns.sol.net said: And I don't like not having anywhere to plug in my power screwdriver's recharger... I suppose I should see if I can find someplace that has a transformer of an appropriate size, or does anyone already have the part number for something that can provide a few hunderd milliamps of 120V from 208? :-) Isn't 208V usually provided as a connection across two phases of a 3 phase circuit? In that case, you get 120V by going between one phase and neutral (no transformer required). You need a NEMA 14 (4 wire) connector to get two phases, neutral, and ground (provides 1 208V circuit and/or 2 120V circuits) or a NEMA L21 (5 wire) connector to get all three phases, neutral, and ground (provides 3 208V circuits and/or 3 120V circuits). -- Chris Adams cmad...@hiwaay.net Systems and Network Administrator - HiWAAY Internet Services I don't speak for anybody but myself - that's enough trouble.
Re: Why choose 120 volts?
Once upon a time, Joe Greco jgr...@ns.sol.net said: And I don't like not having anywhere to plug in my power screwdriver's recharger... I suppose I should see if I can find someplace that has a transformer of an appropriate size, or does anyone already have the part number for something that can provide a few hunderd milliamps of 120V from 208? :-) Isn't 208V usually provided as a connection across two phases of a 3 phase circuit? In that case, you get 120V by going between one phase and neutral (no transformer required). Yes, but this doesn't imply that you have access to those other phases. It is easy enough to be delivered 208V single phase service in a data center environment. ... JG -- Joe Greco - sol.net Network Services - Milwaukee, WI - http://www.sol.net We call it the 'one bite at the apple' rule. Give me one chance [and] then I won't contact you again. - Direct Marketing Ass'n position on e-mail spam(CNN) With 24 million small businesses in the US alone, that's way too many apples.
Re: AH or ESP
I agree as well that ESP-Null the way to go for integrity. From operational perspective if you are supporting both v4 and v6 (and you will) then having different protocols will be a nightmare. Common denominator is ESP-Null. Realistically for IPsec, unless you have the scalable credential issue resolved and easier configs from vendors, the operational time sync will have many looking elsewhere to accomplish what's needed in the name of security. (total bummer IMHO). - merike On May 26, 2009, at 4:35 PM, Jack Kohn wrote: The delusion that network operators can successfully use unhelpful protocols and/or smoke and mirrors to force idealist network design on others needs to end. People use new protocols because they are better. If the benefit of moving to a new protocol does not outweigh the pain of moving to it, people don't use it. That's why the OSI protocols did not kill IP like they were supposed to in the 90s, it is why the largely forgotten mandated move from Windows to secure OSes (ie, Unix) for all government employees never happened, and it is why IPv6 is sputtering. If people want to use NAT, they are going to use NAT. They may stop using it if the widespread adoption of peer to peer protocols means they are missing out on things other people are doing. They are not going to stop using NAT to use a protocol maliciously designed to break it; they will just wait, patiently and nearly always successfully, for somebody to come out with a version that has no such malice. They are certainly not going to stop using NAT because somebody tells them they should use a security protocol that does not secure anything worth securing. BitTorrent is a better anti-NAT tool than AH ever will be. More carrot, less stick. I agree. Folks are going to use ESP-NULL if they really want Integrity Protection .. -Dave
RE: Why choose 120 volts?
See: http://www.3phasepower.org/3phasewiring.htm -Original Message- From: Joe Greco [mailto:jgr...@ns.sol.net] Sent: Tuesday, May 26, 2009 8:20 PM To: Chris Adams Cc: nanog@nanog.org Subject: Re: Why choose 120 volts? Once upon a time, Joe Greco jgr...@ns.sol.net said: And I don't like not having anywhere to plug in my power screwdriver's recharger... I suppose I should see if I can find someplace that has a transformer of an appropriate size, or does anyone already have the part number for something that can provide a few hunderd milliamps of 120V from 208? :-) Isn't 208V usually provided as a connection across two phases of a 3 phase circuit? In that case, you get 120V by going between one phase and neutral (no transformer required). Yes, but this doesn't imply that you have access to those other phases. It is easy enough to be delivered 208V single phase service in a data center environment. ... JG -- Joe Greco - sol.net Network Services - Milwaukee, WI - http://www.sol.net We call it the 'one bite at the apple' rule. Give me one chance [and] then I won't contact you again. - Direct Marketing Ass'n position on e-mail spam(CNN) With 24 million small businesses in the US alone, that's way too many apples.
Re: Why choose 120 volts?
Leo Bicknell bickn...@ufp.org writes: ... http://www.apcmedia.com/salestools/NRAN-6CN8PK_R0_EN.pdf ... But what you'll find in the paper is that the change allows you to re-architect the power plant in a way that saves you money on PDU's, transformers, and other stuff. Thus this makes the most sense to consider in a green field deployment. noting also that architect is a noun, i find that on large plants the cost of copper wire and circuit breakers add up, where sizes (and prices) are based on ampherage not wattage. in the old days when a rack needed 6kW, that was 208V 30A (10 gauge wire) or it was two of 120V 30A (also 10 gauge wire). somewhere near the first hundred or so racks, the price of the wire and breakers starts to seem high, and very much worth halving. once in a while some crashcart CRT monitor won't run on anything but 120V but for $50 NRC it can be replaced with an LCD. everything else that's still worth plugging in (that is, having a power/heat cost per performance better than that of a blow dryer) doesn't care what voltage it lives on. -- Paul Vixie KI6YSY
Re: Colo on the West Coast
Pshem Kowalczyk pshe...@gmail.com writes: (answers can be off-list) See http://www.vix.com/personalcolo/. (updates still welcomed, btw.) -- Paul Vixie KI6YSY
Re: Why choose 120 volts?
On Tue, 26 May 2009 19:51:42 -0400, Chris Adams cmad...@hiwaay.net wrote: Isn't 208V usually provided as a connection across two phases of a 3 phase circuit? In that case, you get 120V by going between one phase and neutral (no transformer required). Indeed it is. If you want to see it yourself, measure the voltage between hots on different circuits. I see 208-212V depending on the legs (they aren't evenly loaded.) This is easier to do in a data center, but with a long extention cord it can be done with the office. :-) (of course, having the building wiring diagram(s) makes for a short hunt.) --Ricky
Re: Why choose 120 volts?
On Tue, 26 May 2009 20:32:54 -0400, Paul Vixie vi...@isc.org wrote: once in a while some crashcart CRT monitor won't run on anything but 120V but for $50 NRC it can be replaced with an LCD. everything else that's still worth plugging in (that is, having a power/heat cost per performance better than that of a blow dryer) doesn't care what voltage it lives on. Or go to Radio Shack and get one of those international traveler power converter packs. I have a number of systems (ok, yes, they're old) that a) do not have autosensing power supplies (someone has to get a paperclip and flip a switch), and b) will not work on 208v -- 120 or 240, but not 208. --Ricky
Re: Why choose 120 volts?
On Tue, May 26, 2009 at 12:39:10PM -0700, Seth Mattinen wrote: I have a pure curiosity question for the NANOG crowd here. If you run your facility/datacenter/cage/rack on 120 volts, why? I've been running my facility at 208 for years because I can get away with lower amperage circuits. I'm curious about the reasons for using high-amp 120 volt circuits to drive racks of equipment instead of low-amp 208 or 240 volt circuits. ~Seth I love 208V but I have to fight almost everytime with our datacenter provider. They got 50 or so Colo's which are all cookie cutter. Then there is our datacenter, the only facility where they can deliver 3-phase and monitor actual power usage. Everytime when we ask for 3-phase it is a fight now. Our latest circuits (50-amp although we won't use more than 16A under normal use (A+B load)), took me 9 months to get out of them. :-( -- Regards, Ulf. - Ulf Zimmermann, 1525 Pacific Ave., Alameda, CA-94501, #: 510-865-0204 You can find my resume at: http://www.Alameda.net/~ulf/resume.html
Re: Why choose 120 volts?
Joe Greco wrote: Once upon a time, Joe Greco jgr...@ns.sol.net said: And I don't like not having anywhere to plug in my power screwdriver's recharger... I suppose I should see if I can find someplace that has a transformer of an appropriate size, or does anyone already have the part number for something that can provide a few hunderd milliamps of 120V from 208? :-) Isn't 208V usually provided as a connection across two phases of a 3 phase circuit? In that case, you get 120V by going between one phase and neutral (no transformer required). Yes, but this doesn't imply that you have access to those other phases. It is easy enough to be delivered 208V single phase service in a data center environment. ... JG Correct. I have a Smart-UPS RT connected across two legs of 3 phase for 208. The unit does not have a neutral, only ground, so it's 3 wires in and 3 out. The output is only 208 L-L with odd voltages on L-G. Since there's no neutral, it can only be used to drive 208 loads or a transformer for 120. ~Seth
Re: The adventures of Team ARIN
At least now we know where all those fees end up. Jeff On Tue, May 26, 2009 at 11:14 AM, Jeroen Massar jer...@unfix.org wrote: Semi-Off-Topic here, I know, but it might help Network Operators to explain certain misguided people and thus lower noise and raise signal in various places. https://www.arin.net/knowledge/comic.html Short short synopsis: comic about how ARIN handles certain things and what ARIN does etc. Greets, Jeroen -- Currently published issues: Issue 1 - The Beginning of Team ARIN - Synopsis: In issue 1, learn how Team ARIN was founded with the assistance of Jon Postel. See how active participation by the entire Internet community is key to Team ARIN's success as it endeavors to facilitate the open and transparent, bottom-up policy development processes. Issue 2 - FUD for Thought - Synopsis: In issue 2, Team ARIN embarks on a mission to raise awareness about the issue of depletion of the available pool of IPv4 addresses and encounters a new enemy -- Agent FUD. Working for the Bad Idea Force, FUD is busy trying to spread fear, uncertainty, and doubt about IPv4 address depletion. Using newly acquired technology, Team ARIN combines forces to help combat this new enemy of the open and transparent principles the Internet is based on, and in doing so creates something more than even they expected! Issue 3 - FUD 2.0 - Return of the FUD Factor! - Synposis: Issue 3 begins with Team ARIN flying back from a conference when they are alerted to a new problem and an old enemy. Agent FUD has returned and this time he's seeking to undermine the Internet community's migration to IPv6. Read the issue to find out how Team ARIN saves the day and how you can help! (s/synposis/synopsis/ by me, that typo is still on the original site, rest of content all by ARIN, nothing I can do about, thus don't complain to me ;) -- Jeffrey Lyon, Leadership Team jeffrey.l...@blacklotus.net | http://www.blacklotus.net Black Lotus Communications of The IRC Company, Inc. Look for us at HostingCon 2009 in Washington, DC on August 10th - 12th at Booth #401.
Re: Why choose 120 volts?
On Tue, 26 May 2009, Joe Greco wrote: Once upon a time, Joe Greco jgr...@ns.sol.net said: And I don't like not having anywhere to plug in my power screwdriver's recharger... I suppose I should see if I can find someplace that has Yes, but this doesn't imply that you have access to those other phases. It is easy enough to be delivered 208V single phase service in a data center environment. Uh. 208v single phase is functionally the same as 240v single phase. You grab 1 hot, neutral off the ground, and you have a common 110v circuit. Even if you're 3 phase to your PDU, it's still single phase to the servers. (specialty gear excluded, but those generally plug direct to the circuit, not to a PDU). This makes it very very easy to solve this problem, and I keep a few of these floating around at all of my datacenters, with big labels saying who they belong too. (ignoring the fact that for drill charging at least there's usually house power available, but crash carts need these...) C14 (M) to 5-15 (F) adaptor cable: http://www.cdw.com/shop/products/default.aspx?edc=1036852 I also use them to run wall warts, etc, as needed. --- david raistrickhttp://www.netmeister.org/news/learn2quote.html dr...@icantclick.org http://www.expita.com/nomime.html
Re: Why choose 120 volts?
Seth Mattinen se...@rollernet.us writes: I have a pure curiosity question for the NANOG crowd here. If you run your facility/datacenter/cage/rack on 120 volts, why? I've spent the last several days going back and forth with salespeople, trying to find a rack with 208v power in the south bay, or a cheap 100M connection from market post tower to heraklesdata in Sacramento. (where I have cheap 208v power) From what I see, most places in the bay area just can't handle the kind of heat density that a 30a 208v circuit per rack would bring. (they won't sell me more than 2 20A 120v circuits, either, and many will only sell me a single 15a circuit per rack. I assume that's an effort to keep the heat output within cooling system capabilities.) But that still doesn't explain why they don't hand out 10a 208v circuits. I've also seen employers pick 208v over 120v even after I pointed out the cost per watt advantages of 208v, even without counting efficiency gains. In one case they provisioned one rack with 208v, because the vendor of some particularly expensive bit of equipment recommended it, then they left all the commodity servers on 120v. Why didn't they put everything on 208v? I pointed out that the cost per watt was lower. Maybe I blew my credibility by wanting to research 48v power supplies for our kit before that? (it was a telco facility, after all, and I was young.) 30a 208v is about perfect for a rack, if you ask me. (I imagine the guys who have to deal with cooling feel differently, but at my scale, that's all priced into the power.) -- Luke S. Crawford http://prgmr.com/xen/ - Hosting for the technically adept We don't assume you are stupid.
Re: The adventures of Team ARIN
https://www.arin.net/knowledge/comic.html Short short synopsis: comic about how ARIN handles certain things and what ARIN does etc. imiho, an embarrassment to arin and to the internet randy
Re: Why choose 120 volts?
On Tue, 26 May 2009, Joe Greco wrote: Once upon a time, Joe Greco jgr...@ns.sol.net said: And I don't like not having anywhere to plug in my power screwdriver's recharger... I suppose I should see if I can find someplace that has Yes, but this doesn't imply that you have access to those other phases. It is easy enough to be delivered 208V single phase service in a data center environment. Uh. 208v single phase is functionally the same as 240v single phase. Yes, functionally, it is. You grab 1 hot, neutral off the ground, and you have a common 110v circuit. Even if you're 3 phase to your PDU, it's still single phase to the servers. (specialty gear excluded, but those generally plug direct to the circuit, not to a PDU). Go tell your electrical inspector that you're using the ground as a neutral. I'll make the popcorn ... put simply, that's not allowed, for Very Good Reasons. This makes it very very easy to solve this problem, No it doesn't, and the following doesn't even seem to relate: and I keep a few of these floating around at all of my datacenters, with big labels saying who they belong too. (ignoring the fact that for drill charging at least there's usually house power available, but crash carts need these...) C14 (M) to 5-15 (F) adaptor cable: http://www.cdw.com/shop/products/default.aspx?edc=1036852 I also use them to run wall warts, etc, as needed. Great, you're the latest person to invent a way to present a 5-15R that offers something besides 120VAC. This is neither new nor novel, but it *is* dangerous and risky, and in no way solves the problem. Plugging a device that is designed to run on 120V into 208V will probably result in (at least!) one of: 1) smoke 2) fire 3) burning components 4) dead device 5) burning batteries (in the case of the aforementioned charger) 6) general excitement and panic in the data center in the event that none of the above happen immediately, but rather some time after you leave. 7) etc. The basic problem here is that there are still many devices out there that do not have autoranging power supplies. As for for drill charging at least there's usually house power available, well, that sucks. We're at Equinix. There are periods where no one uses the drill, or the power screwdriver, for months at a time. With 120V in the cage, I left the chargers hooked up and trickle charging. Neither the drill nor the power screwdriver have autoranging power supplies. So now with 208V, someone has to bring along batteries, because we can't leave them on-site, or they'll go stale. Bleh. ... JG -- Joe Greco - sol.net Network Services - Milwaukee, WI - http://www.sol.net We call it the 'one bite at the apple' rule. Give me one chance [and] then I won't contact you again. - Direct Marketing Ass'n position on e-mail spam(CNN) With 24 million small businesses in the US alone, that's way too many apples.
Re: The adventures of Team ARIN
Date: Wed, 27 May 2009 13:19:55 +0900 From: Randy Bush ra...@psg.com https://www.arin.net/knowledge/comic.html Short short synopsis: comic about how ARIN handles certain things and what ARIN does etc. imiho, an embarrassment to arin and to the internet Initially I thought the same thing, but the feedback from the large number of totally clueless ARIN customers has been overwhelmingly positive. Clearly, the comic book was never intended for the typical subscriber to this list. -- R. Kevin Oberman, Network Engineer Energy Sciences Network (ESnet) Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab) E-mail: ober...@es.net Phone: +1 510 486-8634 Key fingerprint:059B 2DDF 031C 9BA3 14A4 EADA 927D EBB3 987B 3751
