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Re: NTP question
by Scott Weeks 02 May '19

02 May '19

> But wait. What is the GPS constellation goes down? > THEN we have bigger problems :) > -------------------------------------------------- > > > What if the US military intentionally messes with > the signal to thwart the advances of an enemy who > is using GPS in their attack? ;-) ------------------------ --- mel(a)beckman.org wrote: Enemies aren’t dependent on US GPS, by the way. lol! ----------------------------------------------- Oops, but still from the second link: "...which could be disabled or degraded by their operators at any time" Most big countries say the same: "...will provide an alternative global navigation satellite system..." scott Details for the intrested. https://en.wikipedia.org/wiki/GLONASS "Russian...provides an alternative to GPS and is the second navigational system in operation with global coverage and of comparable precision. https://en.wikipedia.org/wiki/Galileo_(satellite_navigation) "...live in 2016,[4] created by the European Union" "...so European nations do not have to rely on the U.S. GPS, or the Russian GLONASS systems, which could be disabled or degraded by their operators at any time" https://en.wikipedia.org/wiki/BeiDou "a Chinese satellite navigation system....Beidou-1 was decommissioned at the end of 2012." "BeiDou-2, became operational in China in December 2011 with a partial constellation of 10 satellites in orbit. Since December 2012, it has been offering services to customers in the Asia-Pacific region." "In 2015, China started the build-up of the third generation BeiDou system (BeiDou-3) for global coverage constellation. The first BDS-3 satellite was launched on 30 March 2015.[5] As of October 2018, fifteen BDS-3 satellites have been launched[6]. BeiDou-3 will eventually consist of 35 satellites and is expected to provide global services upon completion in 2020. When fully completed, BeiDou will provide an alternative global navigation satellite system to the United States owned Global Positioning System (GPS),[7][8] the Russian GLONASS or European Galileo systems and is expected to be more accurate than these https://en.wikipedia.org/wiki/Indian_Regional_Navigation_Satellite_System "...is an autonomous regional satellite navigation system that provides accurate real-time positioning and timing services.[4] It covers India and a region extending 1,500 km (930 mi) around it, with plans for further extension." https://en.wikipedia.org/wiki/Quasi-Zenith_Satellite_System "...a project of the Japanese government for the development of a four-satellite regional time transfer system and a satellite-based augmentation system for the United States operated Global Positioning System (GPS) to be receivable in the Asia-Oceania regions, with a focus on Japan.

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Re: NTP question
by Scott Weeks 02 May '19

02 May '19

--- mel(a)beckman.org wrote: From: Mel Beckman <mel(a)beckman.org> But wait. What is the GPS constellation goes down? THEN we have bigger problems :) -------------------------------------------------- What if the US military intentionally messes with the signal to thwart the advances of an enemy who is using GPS in their attack? ;-) scott

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Re: NTP via GPS
by Scott Weeks 02 May '19

02 May '19

--- fkittred(a)gwi.net wrote: From: Fletcher Kittredge <fkittred(a)gwi.net> On Thu, May 2, 2019 at 12:12 AM Richard <rgolodner(a)infratection.com> wrote: > I found this article very helpful as I knew very little. I was smarter > for reading it though it may be to basic for many: > > https://timetoolsltd.com/gps/gps-ntp-server/ > It is basic and has at least some inaccuracies. I skimmed it and found: "The NTP protocol was originally developed for the LINUX operating system. " Kids these days.... so much history lost. For those under 60 revolutions of the sun: NTP and related protocols far pre-date Linux. Linux is a relatively late arriving implementation of Unix. The vast majority of intellectual property behind Linux was from prior variants of Unix; Linux was just a free, unencumbered version that was widely adopted. ----------------------------------------------- https://tools.ietf.org/pdf/rfc958.pdf Network Working Group D.L. MillsRequest for Comments: 958 M/A-COM Linkabit September 1985 Network Time Protocol (NTP) No linux in 1985... scott

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Optical routes from MI-OH regionals
by Jason Lixfeld 02 May '19

02 May '19

Hi, Looking for someone who might have routes (lit or dark) from Detroit, MI to Columbus, OH preferably using a straight’ish shot from Toledo to Columbus. Most routes I’ve seen from the larger providers tend to run Toledo - Lima - Columbus or Toledo - Cleveland - Columbus, so I’m hoping a smaller regional player may have something more direct. Thanks in advance!

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NTP via GPS
by Richard 02 May '19

02 May '19

I found this article very helpful as I knew very little. I was smarter for reading it though it may be to basic for many: https://timetoolsltd.com/gps/gps-ntp-server/ Richard

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Re: NTP Question
by James R Cutler 02 May '19

02 May '19

On Wed, May 01, 2019 at 02:35:58PM -0700, Harlan Stenn wrote: > - Why do folks want to have one or more NTP server masters that have at > least 1 refclock on them in a data center, instead of having their data > center NTP server masters that only get time over the internet? Answers to that include: Keeping the Auditors happy Knowing that “everyone does it” - the vendor told them so Bragging rights (expensive hardware) Being unbothered by fighting with facilities for building penetrations and antenna mounts Misunderstanding the beauty and economy Dave Mills marvelous algorithms for consistent time based on multiple sources, even those connected via internet Unwillingness or inability to leverage other local resources capacity to run ntpd with minimal impact in order to have a good constellation of local NTP servers Willingness to farm out time service without doing a deep dive into why and how, just leaving the design to the appliance vendors This covers most of what I have encountered in providing enterprise time services for $dayjob+clients. I probably left out some significant points, but it has been a few years...

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AT&T contact
by Mehmet Akcin 01 May '19

01 May '19

Peering email is broken, looking for an AT&T contact. Please contact me off list. The original message was received at Tue, 30 Apr 2019 16:11:17 -0400 from m0053301.ppops.net [127.0.0.1] ----- The following addresses had permanent fatal errors ----- <peering(a)att.com> (reason: 550 5.1.1 <peering(a)att.com>... User unknown) ----- Transcript of session follows ----- ... while talking to [144.160.112.16]: >>> DATA <<< 550 5.1.1 <peering(a)att.com>... User unknown 550 5.1.1 <peering(a)att.com>... User unknown <<< 503 5.0.0 Need RCP -- Mehmet +1-424-298-1903

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DSL\POTS Testing Equipment
by Mike Hammett 01 May '19

01 May '19

We've got an EXFO Colt-250 and an EXFO CableSHARK P3. They're 10 - 15 years old, but as far as I know they work. Practically, what am I missing out on by not getting a newer tester? I'd like the CableSHARK's features in a smaller unit, but it seems like we're looking at a minimum of $2k to get something that does that. ----- Mike Hammett Intelligent Computing Solutions http://www.ics-il.com Midwest-IX http://www.midwest-ix.com

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looking for hostname router identifier validation
by Matthew Luckie 01 May '19

01 May '19

Hi NANOG, To support Internet topology analysis efforts, I have been working on an algorithm to automatically detect router names inside hostnames (PTR records) for router interfaces, and build regular expressions (regexes) to extract them. By "router name" inside the hostname, I mean a substring, or set of non-contiguous substrings, that is common among interfaces on a router. For example, suppose we had the following three routers in the savvis.net domain suffix, each with two interfaces: das1-v3005.nj2.savvis.net das1-v3006.nj2.savvis.net das1-v3005.oc2.savvis.net das1-v3007.oc2.savvis.net das2-v3009.nj2.savvis.net das2-v3012.nj2.savvis.net We might infer the router names are das1|nj2, das1|oc2, and das2|nj2, respectively, and captured by the regex: ^([a-z]+\d+)-[^\.]+\.([a-z]+\d+)\.savvis\.net$ After much refinement based on smaller sets of ground truth, I'm asking for broader feedback from operators. I've placed a webpage at https://www.caida.org/~mjl/rnc/ that shows the inferences my algorithm made for 2523 domains. If you operate one of the domains in that list, I would appreciate it if you could comment (private is probably better but public is fine with me) on whether the regex my algorithm inferred represents your naming intent. In the first instance, I am most interested in feedback for the suffix / date combinations for suffixes that are colored green, i.e. appear to be reasonable. Each suffix / date combination links to a page that contains the naming convention and corresponding inferences. The colored part of each hostname is the inferred router name. The green hostnames appear to be correct, at least as far as the algorithm determined. Some suffixes have errors due to either stale hostnames or incorrect training data, and those hostnames are colored red or orange. If anyone is interested in sets of hostnames the algorithm may have inferred as 'stale' for their network, because for some operators it was an oversight and they were grateful to learn about it, I can provide that information. Thanks, Matthew

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Help needed to validate results of topology discovery research
by Bahador Yeganeh 30 Apr '19

30 Apr '19

Hi Nanog members, I am senior PhD student with the Oregon Network Research Group ( https://onrg.gitlab.io) at the University of Oregon, and sending this email to seek your help for validating the research results for one of our network measurement projects. We have conducted a large scale measurement study to infer the private (both physical and virtual) and public interconnections between Amazon/AWS network and all other ASes across the Internet along with their metro area where they are located. More information about this project can be found at https://ix.cs.uoregon.edu/~byeganeh/cloudx/. We are interested in validating at least part of our results against ground truth. If you are managing an AS that has one or more direct peerings with any of Amazon's networks (AS7224, AS16509, AS19047, AS14618, AS38895, AS39111, AS8987, and AS9059) and aware of their IPs and locations, it would be extremely valuable if you could validate our inferred peering between your AS and Amazon at the *aggregate level *(i.e. just indicating what fraction of our inferred interconnections for your network is correct). We will report this aggregate result in our study without revealing the identity of your network. If you have any questions or need more information about this project, please feel free to contact me. I appreciate your prompt response as we are trying to submit this study to a conference in a few weeks. Regards, Bahador Yeganeh

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