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Re: floods
by fehnb＠jerseycape.net 28 Jun '97

28 Jun '97

Looks like the same one. As I recall, he got many, many answers. Some even addressed his question.... >Did this message get lost in a temporal warp about >3 months long or so? I seem to remember a thread >> >> I'm doing a project for school.Can you help?what is the scientific >> principle for floods?Thanks! > > Robert J. Fehn Sr.,President and CEO Senior Systems Engineer, Jersey Cape Information Systems Inc. "Access, Engineering, Microwave Links, Consulting, Design."

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Re: Internet Backbone Index
by Sean Donelan 28 Jun '97

28 Jun '97

Ok, so I said I wasn't going to comment on the methodology, I lied. I wouldn't say the Keynote study is the worst ever. There are some really rotten studies in the fields of psychology and sociology. Since the Boardwatch/Keynote study didn't 'test' DRA Net, I guess I'm one of the few independent, disinterested parties to comment on the study's methods. A problem with the Keynote study is it seems very dependent on the location, type and connections of the testing platforms. Keynote mentions that connections from Dallas and Phoenix were slow to 'every' backbone site. This would indicate some systematic problem with the testing sites. Perhaps the results are even more dependent on the testing systems than the systems under test. There are also problems with outlier data points. For example, elsewhere on the Keynote site, the MCI web site had very fast access from 28 test sites (< 4secs), and very slow access from one test site in philly (> 14secs). Mixing and matching data points, if you left out the one outlier data point, MCI would have been faster than Savvis. So I don't know if the rankings are very meaningful if a single test site can have such a pronounced effect. Unlike a scientific study, there doesn't seem to be enough information to independently reproduce the results, so I'm just going from the bits and pieces I can glean from the Keynote pages, press release, and article. >Concerning Internet performance, there have always been a variety of ways >of measuring it. It all depends on what you are really trying to measure. >The Keynote study is attempting to measure something to which the average >Internet user (not engineers) can relate. However, There are also clearly >the possibility of artifacts in the data because of the testing machine's >TCP stack or other issues (Vern Paxson has covered these issues at NANOG >and IETF meetings over the last few years). Checking their web site, their >software appears to run on top of the TCP stacks of many systems, so the >known artifacts of some of these platforms could be an issue. -- Sean Donelan, Data Research Associates, Inc, St. Louis, MO Affiliation given for identification not representation

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Re: Keynote/Boardwatch Internet Backbone Index A better test!!!
by Jack Rickard 28 Jun '97

28 Jun '97

Randy: I'm with you to a point. But NONE of the measurements were taken from Jack's house. None were taken from Boardwatch's office. And in fact, the measurements were taken from 27 different geographic locations. I think that is a somewhat critical element here. We failed to come up with a methodology that could be performed from "Jack's House" without primarily measuring "Jack's connectivity" more than anything else. Obviously, that is what I would have liked. Never could come up with an idea on how to do that effectively. Inverse technology appears to be in the business of selling $50,000 marketing reports to order for anyone with $50,000.00. How would that be apt? Finally, I'm amazed at how "trivial it is to point out useless and devoid of meaning this is", when you haven't seen the results yet. It might be even EASIER once you've READ them. Jack Rickard ---------- > From: Randy Bush <randy(a)psg.com> > To: nanog(a)merit.edu > Subject: Re: Keynote/Boardwatch Internet Backbone Index A better test!!! > Date: Friday, June 27, 1997 3:00 PM > > I want to measure the response of each ISP's marketing department. So I > will send a certified letter to their office of record in Deleware, and > report how long before I get the receipt back. Maybe I well do this for 30 > letters to get better data. > > So, we now have an interesting report of the accessibility of various ISPs' > web servers from Jack's house. While it is trivial to point out how useless > and devoid of meaning this is, what is a wee bit harder is to describe what > would be a useful measure to Jack's audience and how that might be obtained. > > Ben Black's pointing out http://www.inversenet.com/about/backgrounder.html#2 > may be *very* apt, and somewhat ingenious, considering Jack's audience. > > Are there other good ideas or examples? > > randy

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Re: Cisco access-lists ???
by Danny McPherson 28 Jun '97

28 Jun '97

to expand a bit .. i created an acl to match all prefixes longer than a /19: > access-list 101 permit ip any 255.255.240.0 0.0.15.255 and an acl to match everything else: > access-list 102 permit ip any any i created route-map "damp": > route-map damp permit 10 > match ip address 101 > set dampening 30 750 2000 90 > ! > route-map damp permit 20 > match ip address 102 > set dampening 15 750 2000 60 in the first sequence (10) of the route-map, i match all prefixes longer than a /19 (via acl 101) and apply the following dampening thresholds: half-life= 30 minutes reuse-value= 750 suppress-value= 2000 max-supress= 90 minutes in the second sequence i match everything else (via acl 102) and applied cisco's default values: halflife= 15 minutes reuse-value= 750 suppress-value= 2000 max-suppress= 60 minutes i then applied the route-map to bgp dampening: > router bgp 65534 > bgp dampening route-map damp each time a route flaps it gets a penalty - 1000. if the cumulative penalty is greater than the suppress-value (2000 here, so 3 flaps), the advertisement of the route will be suppressed. the penalty will be exponentially decayed based on the half-life. once the penalty decreases below the reuse-value (750 here), the advertisement will be unsuppressed. using cisco's defaults (the second sequence), if a route flaps a lot in a very short period then becomes stable, it will only be suppressed for a maximum of 1 hour. with the first sequence, the half-life is doubled and the maximum amount of time a route that has become stable will be suppressed is 90 minutes .. basically. back to the floods... -danny

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RE: floods
by Sanjay Dani 28 Jun '97

28 Jun '97

>Here's the original one (different guy).... > >Unless its one of JF's friends getting us to waste cycles, my guess is >that these kids are entering "floods" into a search engine, and are >sending spam quantities of requests for info for their projects. I guess >"SYN floods" gets the search engine's attention... Today's "floods" poster probably meant it as a joke to spare us from the "backbone performance" drivel..

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RE: floods
by Rodney Joffe 28 Jun '97

28 Jun '97

Here's the original one (different guy).... Unless its one of JF's friends getting us to waste cycles, my guess is that these kids are entering "floods" into a search engine, and are sending spam quantities of requests for info for their projects. I guess "SYN floods" gets the search engine's attention... NANOG Archives - April 97: +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ From: Hoisl(a)aol.com Received: (from root@localhost) by emout28.mail.aol.com (8.7.6/8.7.3/AOL-2.0.0) id UAA10131 for nanog(a)merit.edu; Tue, 8 Apr 1997 20:25:17 -0400 (EDT) Date: Tue, 8 Apr 1997 20:25:17 -0400 (EDT) Message-ID: <970408201957_-1234896358(a)emout08.mail.aol.com> To: nanog(a)merit.edu Subject: floods Sender: owner-nanog(a)merit.edu I am doing a project for school and I was wondering if you could answer my question. What can be done to reduce the amount of flood damage? Thanks. Rodney Joffe Chief Technology Officer Genuity Inc., a Bechtel company http://www.genuity.net > -----Original Message----- > From: fehnb(a)jerseycape.net [SMTP:fehnb@jerseycape.net] > Sent: Friday, June 27, 1997 8:44 PM > To: nanog(a)merit.edu > Subject: Re: floods > > Looks like the same one. As I recall, he got many, many answers. Some > even > addressed his question.... > > >Did this message get lost in a temporal warp about > >3 months long or so? I seem to remember a thread > >> > >> I'm doing a project for school.Can you help?what is the scientific > >> principle for floods?Thanks! > > > > > > Robert J. Fehn Sr.,President and CEO > Senior Systems Engineer, Jersey Cape Information Systems Inc. > "Access, Engineering, Microwave Links, Consulting, Design." > >

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Re: Keynote/Boardwatch Internet Backbone Index A better test!!!
by Joseph McDonald 28 Jun '97

28 Jun '97

"Peter E. Giza" <giza(a)adsmart.net> writes: > Okay, point taken, we'll wait until we get the 35 "color glossy photos > with the lines and arrows and a paragraph on the back of each one to > explain what each picture means" and then decide how useless/useful the > info is. SO now lets _drop_ it. LOL! I'm sure rick(a)ar.com will get a kick out of that one! -joe

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Re: Cisco access-lists ???
by Danny McPherson 28 Jun '97

28 Jun '97

something like this ("in cisco parlance" :-) should do the trick: router bgp 65534 bgp dampening route-map damp ! access-list 101 permit ip any 255.255.240.0 0.0.15.255 access-list 102 permit ip any any ! route-map damp permit 10 match ip address 101 set dampening 30 750 2000 90 ! route-map damp permit 20 match ip address 102 set dampening 15 750 2000 60 you can see the effects from the output below. in short, i've tightened the thresholds on prefixes longer than /19. lab2-7507#sh ip bgp fla BGP table version is 91081, local router ID is 207.240.2.3 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal Origin codes: i - IGP, e - EGP, ? - incomplete Network From Flaps Duration Reuse Path *d 215.1.0.0 207.240.2.2 4 00:02:35 00:58:30 65533 *d 215.1.0.0/20 207.240.2.2 4 00:02:35 00:58:30 65533 *d 215.1.0.0/16 207.240.2.2 4 00:02:35 00:28:40 65533 lab2-7507# we're currently not dampening based on prefix length yet, although we are experimenting with it. -danny > > The 'discussion' of Jack's report seems to have overwhelmed an actual > operational question. I am shocked and surprised. > > In cisco parlance, such an entry might be > > access-list 142 deny ip any 255.255.255.128 0.0.0.127 > > which blocks any prefix longer than a /24. > > As to how to express the dampening in the report you mention, could someone > who has it actually installed (come on RV, SD, ...) and debugged please > post? I have exceeded my error quota for the day. Thanks. > > randy

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Re: Keynote/Boardwatch Internet Backbone Index A better test!!!
by Philip J. Nesser II 28 Jun '97

28 Jun '97

We have all seen the results of the survey now and there is a lot of opinion that there are many flaws in the logic. So the question is what is a legitimate test? I remember At the Ann Arbor NANOG there was a report on a project to test reachability, what is the current status of that project? Is there any strong consensus to perform a similar test that is engineered without the flaws in this test? ---> Phil

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Re: Internet Backbone Index
by Jack Rickard 28 Jun '97

28 Jun '97

---------- > From: Ben Black <black(a)zen.cypher.net> > To: Jack Rickard <jack.rickard(a)boardwatch.com> > Cc: Justin W. Newton <justin(a)priori.net>; nanog(a)merit.edu > Subject: Re: Internet Backbone Index > Date: Friday, June 27, 1997 7:07 PM > > On Fri, 27 Jun 1997, Jack Rickard wrote: > > > > > I don't think I'm missing it. I think I'm disagreeing with it in as nice > > and nonconfrontational a way as I can given the crappy personality I have > > apparently your definition of nonconfrontational includes calling people > morons. i think i will expand my definition of "editor" to include > clueless network engineer wannabes. As I recall, you specifically began the name calling episode. > > > to work from. Splitting hairs from here to infinity on what "network" > > means and what the world wide web is departs rather widely from my mission > > here, so I'm giving it short shrift. If you don't know how ping and > > traceroute vary from data flows, I can't help much there either. > > > > since you obviously don't know a thing about how things like peering, > NAPs, IP routing, and all the other components of network engineering > work, i this it humorous. Actually I know quite a bit about them. If it is obvious to you otherwise, it becomes rather obvious that you don't. > > > If you want to draw a line of demarcation between a network and its > > performance, and a web server and its performance, you're free to do so. I > > just probably won't buy into it. > > > > and we probably wouldn't either. but since that isn't what anyone is > doing, how is this relevant? > > > On the actual concept that changing all the web servers will move the > > numbers: It might. It might not. I would probably bet at this point that > > there will be a lot of that going on among the non-moron crowd. I'm kind > > of hoping for it anyway. And then we'll see if the numbers move. My sense > > is that they will move some, and not as much as most seem to think. But > > it's true it could go the other way and be dramatic. I'm open to whatever > > results derive. > > > > so you are hoping backbone providers move their own home page web servers > in order to skew a severely limited and obviously bogus benchmark? if it > is as easy as that to change the results, don't you think perhaps there > is something radically wrong with your methodology? wouldn't that seem > to indicate this so-called benchmark isn't really testing what it > purports to? > I don't think it will be that easy, which if you could read you would see in the comments you quoted. No, I don't think there is something radically wrong with the methodology. I have no hopes for what providers do. They can do whatever they like. We will continue to publish test results. How they react to them is no affair of mine. >

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