March 1997 - Test - lists.nanog.org

Re: The Big Squeeze
by Eric Kozowski 04 Mar '97

04 Mar '97

>>From a single data point on my router, /24's currently account for 64% of >>the routing table entries and for 65% of the flapping prefixes. /16's >>account for 12% of the routing table entries, and 10% of the flapping >>prefixes. It doesn't appear to me there is a significant difference >>between flap behaivor of long prefixes and short prefixes. There are >>more long prefixes than short prefixes. But as a group they both tend >>to flap the same proportion of 2% of the routes within the group. > >Sorry, I'm not convinced this is the case. There is not enough >empirical evidence. Is there any empirical evidence to show otherwise? Id' be interested in seeing it. -- Eric Kozowski Senior Network Engineer eric(a)structured.net Structured Network Systems, Inc. (503)525-9375 FAX http://www.structured.net/ (800)881-0962 Voice PGP Key fingerprint = 2E 5F 3E 6D AA 61 AA 14 D8 FB A4 15 CE 2C D8 8C 'They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety.' -- Benjamin Franklin 1759

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Re: The Big Squeeze
by Sean Donelan 03 Mar '97

03 Mar '97

>Computational power required for a route flap is not the issue here. > >Many people have stated that, statistically longer prefixes flap >more. Unfortunately, they have then said that because of this shorter >prefixes should have looser dampening parameters put on them, when >what they really meant was that the longer prefixes should have more >strict dampening parameters put on them. Yes it is exactly the same >thing, but it is an important semantic distinction. If a group of >prefixes categorized by a its length tends to flap more than the >average, then said group should have more strict dampening parameters >placed on it. Statistics are soo much fun. >From a single data point on my router, /24's currently account for 64% of the routing table entries and for 65% of the flapping prefixes. /16's account for 12% of the routing table entries, and 10% of the flapping prefixes. It doesn't appear to me there is a significant difference between flap behaivor of long prefixes and short prefixes. There are more long prefixes than short prefixes. But as a group they both tend to flap the same proportion of 2% of the routes within the group. -- Sean Donelan, Data Research Associates, Inc, St. Louis, MO Affiliation given for identification not representation

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Caveat Emptor....
by Tony Li 03 Mar '97

03 Mar '97

This is somewhat off topic, but there's no better place... It has come to my attention that a certain significant router vendor's representatives have told some of their prospects that I've worked on their system. Just to set the matter straight, my total employment for the past 6 years has been either at Juniper Networks or at Cisco Systems (or at cisco Systems ;-). If you've heard otherwise, I would very much appreciate hearing from you as I'm contemplating legal action... So far, I have no reason to believe that this is the policy of the aforementioned vendor. In fact, I suspect that it's an overzealous salesdroid. Caveat Emptor. Thank you for your attention. We now return you to your regularly scheduled drivel. ;-) Tony

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Re: "routing table slots" and the real problem
by Justin W. Newton 03 Mar '97

03 Mar '97

At 06:16 PM 3/3/97 -0500, Nathan Stratton wrote: >On Mon, 3 Mar 1997, Gary Zimmerman wrote: > >> Has anyone looked at Ascend's (NetStar Gigarouter). We have and like the >> direction. If they continue to deliver, I think they are going in the >> right direction. Still some parts missing, I hope we can hold on until >> they get here, but the direction is right. I think the open idea is the >> only way to go on this issue. > >We have been using them for about 5 months now, and I like them a lot. We >have worked with Ascend to fix a large numbers of problems. They are very >stable now, and have a lot of people working to make them better. Out of curiosity, where in your network are you using them? What kind of traffic loads are they seeing, etc etc? Justin Newton Network Architect Erol's Internet Services ISP/C Director at Large

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Re: "routing table slots" and the real problem
by garyz＠savvis.com 03 Mar '97

03 Mar '97

Has anyone looked at Ascend's (NetStar Gigarouter). We have and like the direction. If they continue to deliver, I think they are going in the right direction. Still some parts missing, I hope we can hold on until they get here, but the direction is right. I think the open idea is the only way to go on this issue. Gary Zimmerman Savvis Communications http://www.savvis.com email: garyz(a)savvis.com "The only limits are those of vision." ---------- > From: Joseph T. Klein <jtk(a)titania.net> > To: nanog(a)merit.edu; Paul Ferguson <pferguso(a)cisco.com> > Subject: Re: "routing table slots" and the real problem > Date: Sunday, March 02, 1997 5:25 AM > > Warning -- I feel a diatribe emerging. ;-) > > Afordability is primarily a question of how large your existing > base of legacy routers is and your cash flow. > > You can build a box using a free versionof Unix (FreeBSD, NetBSD, > Linux, or whatever your religion of the day), off the shelf > hardware, and gated to route a full backbone routing table > (memory and CPU are cheap) for less than $3K. This is less > than the cost of a single interface card for a Cisco 7xxx! > > Kids; do not try this at your gateway without adult supervision. > :-) > > We are re-designing the Internet to make up for the fact the > largest manufacturers of routers has been slow to develop and > deploy systems that can keep up with the growth curve. A lot of > this comes down to size of the memory bus on low cost systems. > > If port density was not so poor on general purpose hardware, we > would have been far better off deploying "open systems" for routers > rather than what exists today. > > I have always liked my Ciscos, but I truly love routing with my Unix > systems running gated. ... now If I could find some cheap channelized > DS-3 cards for a DEC AlphaStation 500. ;-) > > I may be talking out of my hat here, but I suspect a DEC AlphaStation > 500 with 256M of RAM ranks pretty well against a 75xx. > > Somebody, dig up the stats for me ... > > If router manufacturers worked on hardware and all used an open > software standard ... such as gated ... we would all be better off. > Open standards allow all of us to benefit from the work of others. > The old Unix Guru's mantra is 'build on the works of others.' > > Let us not make the mistakes of the 1890s and associate domination > of the market by oligopolies as good capitalism. Big corporations, > like big government, tend to move slowly. > > Open markets NOT dominated by a single large player is GOOD > capitalism. It increases the pace of innovation and prevents > price fixing. It makes for a healthy, dynamic, marketplace. > > This holds true for routers, backbone providers, toasters > and operating systems (sorry Bill) > > open standards = open markets > > Open standards prevent the failures of a single market > player from inhibiting the growth of the industry. > > Open standards lower the cost to upgrade large installed > systems. > > Reductions in the federal budget are squeezing R&D expenditures in > the US to an all time low. Large corporate downsizing and corporate > mergers have done the same for most large corporations. The bulk > of innovation in the US will come from small companies and > development consortiums. > > It is from these that the next generations of routers will > come. Open standards make the rapid utilization of new > technologies possible and fuel the growth of small companies. > > The Internet is a great place for consorting on standards. > This is what is cool about the IETF! > > Standards do not keep the big boys from playing ... > Cisco and Bay could easily join in an open standard > for router software. It would not be hard to have interoperability > between the IP portions of IOS and gated. > > IOS is the PL-1 of routers. Bay's management reminds me of CICS. ;-) > > Back to the subject ... > > You CAN also use the RA (where available) to reduce your routing > overhead, save memory and reduce CPU usage. (The RA runs a hacked > version of gated that calculates large routing tables quite well.) > > Hmm ... > > router $100,000 amortized over 3 years = 2,800/month > going DS-3 price at a NAP with line = 7,000/month > engineer $70,000 per year min. = 5,900/month > overhead for a small company = 20,000/month > > $50+/month/mile for OC-3 lines ... don't even talk about > local loop costs! > > Routers connect customers. > customers = cash flow. > > The highest cost of running a national network is not buying routers, > it is bandwidth, staff, and administrative overhead. > > Router cost is primarily a factor for smaller networks with limited > cash flow. > > I contend ... > > It is the ISPs who try to be dual homed with 'routing tricks' rather > than using edge routers that can process a core routing table, who > contribute most to routing instability. > > Boardwatch stated that 14% of ISPs are dual homed. I would bet > that 70% of those do not use routers capable of processing a core > routing table. > > Anybody have any stats? > > We need cheap routers that run BGP4 and can eat a core routing table. > 2501s just don't hack it in dual homed configurations ... and most > small guys just don't wish to blow $50,000 on putting 7505s at the > edges of their networks. > > > --- On Sun, 02 Mar 1997 13:48:46 -0500 Paul Ferguson <pferguso(a)cisco.com> wrote: > > At 01:39 PM 3/2/97 -0500, Perry E. Metzger wrote: > > > > > > > >True enough. Of course, this doesn't mean that we can't have routing > > >table growth, as we will have processor capacity growth, but it does > > >mean that the growth of the routing tables must be kept in line with > > >what the router processors can do. > > > > > > > True enough. However, it might also be novel to keep the cost > > down to a level that people can actually afford. > > > > - paul > > > > ---------------End of Original Message----------------- > > -- > From: Joseph T. Klein, Titania Corporation http://www.titania.net > E-mail: jtk(a)titania.net Sent: 13:25:09 CST/CDT 03/02/97 > > "They that can give up essential liberty to obtain a little temporary > safety deserve neither liberty nor safety." > -- Benjamin Franklin, 1759

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Re: Routing Protocol Simulators -Reply
by neal castagnoli 03 Mar '97

03 Mar '97

Craig, Novell built one for NLSP. NLSP models the IS - IS protocol for IPX. The simulator creates a variety of topologies, allows you to specify change rates in those topologies, and also allows you to create your own. Some of the topologies are a cube, one that models what an ISP deploying IPX might look like, and one that models RIP. I'm not sure whether additional topologies have been added. You can contact AE Natarajan for more information (he is copied on this email message). --Neal >>> "Craig A. Haney" <craig(a)seamless.kludge.net> 02/28/97 03:43pm >>> At 18:02 -0500 2/28/97, Daniel O Awduche wrote: >I am in need of routing protocol simulators, and would be >most appreciative if information can be provided on >available packages (commercial and/or public domain). >In particular, packages that can provide realistic >simulation of the ISIS and/or OSPF protocols would be >most ideal. > >Thank you for your time. > >Daniel Awduche. >awduche(a)zonker.ecs.umass.edu Try calling Prof. Ranbir Sidu. Their product may be of interest. TeleniX Corporation (TELENIX-DOM) 3982 White Rose Way Ellicott City, MD 21042-5822 USA Domain Name: TELENIX.COM Administrative Contact: Sidhu, Ranbir (RS2941) telenix(a)ACCESS.DIGEX.NET (410)750-3213 Technical Contact, Zone Contact: Clark Internet Services, Inc. (CIS5-ORG) dns(a)CLARK.NET (410) 995-0550 Fax- (410) 995-0495 Billing Contact: Sidhu, Ranbir (RS2941) telenix(a)ACCESS.DIGEX.NET (410)750-3213 Record last updated on 20-Jan-97. Record created on 01-Aug-96. -craig -------------------------------------------------------------------- Craig A. Haney Cando Consulting - The Internetwork People 703.448.9826 :Tel 2031 Madrillon Springs Court 703.448.9786 :Fax Vienna, VA 22182-3764 http://seamless.kludge.net

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Frame Relay Question
by Scott Reubelt 03 Mar '97

03 Mar '97

I have a question that could or should be able to be answered by this group. I'm looking to simulate a Frame Relay Internet environment between a couple of routers. This will be internal and not connected to the internet, yet. I will also need the ability to add nodes to this simulated WAN. Does someone have a quick and dirty HW & SW list that I will need to purchase?? Thanks, -- Scott F. Reubelt sreubelt(a)whistle.com (http://www.whistle.com)

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Re: "routing table slots" and the real problem
by Paul Ferguson 03 Mar '97

03 Mar '97

At 01:39 PM 3/2/97 -0500, Perry E. Metzger wrote: > >True enough. Of course, this doesn't mean that we can't have routing >table growth, as we will have processor capacity growth, but it does >mean that the growth of the routing tables must be kept in line with >what the router processors can do. > True enough. However, it might also be novel to keep the cost down to a level that people can actually afford. - paul

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Re: The Big Squeeze
by Sean Donelan 03 Mar '97

03 Mar '97

>> I would suggest that the largest percentage of flapping prefixes in the >> global routing system belong to prefixes longer than /19. > >Hence the convention to damp differently for different lengths. See one of >the foils in http://www.psg.com/~randy/970210.nanog/, which suggests that we >over here start following the European lead on this. Is the route computation of a /8 prefix flapping once a second any different than a /24 flapping once a second? If /8's are "naturally" more stable, then why allow them to flap more before dampening them? When dampening was first being rolled out I remember one of the early networks that got hit was PSI's net 38/8. Treating flapping prefixes differently based on length has more to do with how many people scream when prefixes covering a large amount of address space get dampened than the impact of the route flap of an individual prefix on the router. Although most folks have permanently filtered it, isn't 1/8 still the flappiest prefix of all. -- Sean Donelan, Data Research Associates, Inc, St. Louis, MO Affiliation given for identification not representation

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Re: Frame Relay Question
by Kenneth E. Gray 03 Mar '97

03 Mar '97

Depends on how you want to simulate the frame. A cisco router can act as a switch, but it doesn't FECN or BECN...so, if you're actually testing newer features like Frame Relay Traffic Shaping you would be hard pressed to see any benefit 8^). However, quick and dirty emulation can be done with an old cisco router (I personally use an AGS+ running 10.3 - the highest it can go - with a ton of serial ports). At 04:37 PM 3/3/97 +0000, Scott Reubelt wrote: >I have a question that could or should be able to be answered by this >group. > >I'm looking to simulate a Frame Relay Internet environment between a >couple of routers. This will be internal and not connected to the >internet, yet. I will also need the ability to add nodes to this >simulated WAN. Does someone have a quick and dirty HW & SW list that I >will need to purchase?? > >Thanks, >-- > >Scott F. Reubelt >sreubelt(a)whistle.com (http://www.whistle.com) > > Ken Gray || || ISP Systems Engineer || || Reston, Virginia USA |||| |||| tel: +1.703.397.5942 ..:||||||:..:||||||:.. e-mail: kegray(a)cisco.com c i s c o S y s t e m s fax: +1.703.397.5999

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