From owner-freebsd-isp Sat Sep 14 11:21:29 1996 Return-Path: owner-isp Received: (from root@localhost) by freefall.freebsd.org (8.7.5/8.7.3) id LAA29254 for isp-outgoing; Sat, 14 Sep 1996 11:21:29 -0700 (PDT) Received: from pinky.junction.net (pinky.junction.net [199.166.227.12]) by freefall.freebsd.org (8.7.5/8.7.3) with SMTP id LAA29247 for ; Sat, 14 Sep 1996 11:21:26 -0700 (PDT) Received: from sidhe.memra.com (sidhe.memra.com [199.166.227.105]) by pinky.junction.net (8.6.12/8.6.12) with ESMTP id XAA27584; Fri, 13 Sep 1996 23:51:23 -0700 Received: from localhost (michael@localhost) by sidhe.memra.com (8.6.12/8.6.12) with SMTP id AAA25173; Sat, 14 Sep 1996 00:35:44 -0700 Date: Sat, 14 Sep 1996 00:35:42 -0700 (PDT) From: Michael Dillon To: Small Internet Access Providers cc: inet-access@earth.com, linuxisp@jeffnet.org, freebsd-isp@freebsd.org, os2-isp@dental.stat.com Subject: Re: Internet MELTS DOWN AT END 1996?? In-Reply-To: Message-ID: Organization: Memra Software Inc. - Internet consulting MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-isp@freebsd.org X-Loop: FreeBSD.org Precedence: bulk On Sat, 14 Sep 1996, Hubert Savelberg wrote: > What is your opinion/experience about the published statement in: > > http://www.boardwatch.com/mag/96/sept/bwm17.htm The guy is clueless and any ISP that looks to him for advice is even more clueless. A) Customers do not call and complain about sites greater than 30 hops away because they don't know this. The actual network diameter has been shrinking recently due to more exchange points and NAP's in operation so the 30 hop limit is highly unlikely to be reached. B) Yes your upstream might call you and tell you to renumber at any time. But you should know this ftp://rs.internic.net/policy/internic/internic-ip-1.txt and you should be prepared for this http://www.isi.edu/div7/pier and your provider will give you the time you need to renumber and reconfigure things. This is a fact of life everywhere in the world if you are a small ISP on today's Internet. C) Since you know all about renumbering in advance you should already have your customers ready to renumber painlessly or they should already be insulated from renumbering by using NAT's and RFC1918 addresses. Therefore there should be no fallout. D) If your network connection is not performing as it should, then you should know today! not tomorrow. You should be analyzing performance on a continuing basis and upgrading as needed to avoid bottlenecks. Loopback testing is just plain silly unless your tests show that your T1 can't handle a 1.54mbps to the next hop router. E) Sprint is not turning away small ISP traffic. They merely have a policy that filters traffic from small unaggregated networks. The word "unaggregated" is the key here because if your IP addresses come from your upstream provider then your small network *WILL* be aggregated and Sprint's filters will not affect you. F) This use of the words "dampen" and "meltdown" are completely out of context and have nothing to do with small ISP's at all. When large ISP's who run dynamic BGP routing protocols run into problems and oscillate between withdrawing and announcing routes, all the tier 1 NSP's (not just Sprint) dampen their BGP sessions to prevent the routers in the network core from being overloaded with too many adds and deletes in the routing tables. Meltdown is a cute way to say overload. G) This thing about trade laws is silly. Trade laws have no effect whatsoever on technology and technical capability. If there was a law that an airline could not refuse you a seat on an airline if you were there an hour ahead of time, would it make any difference? No, because when the plane is full, it is full and laws cannot change that. H) He attempts to make it seem as if the IETF is guaranteeing that there will be an Internet meltdown this year. Not true. Bob Metcalfe is predicting such a meltdown and he is probably an IETF member along with thousands of others who do not believe any meltdown is imminent. I) The Internet has *ALWAYS* been on the verge of collapse and probably always will be. This is better known as the free market as opposed to a monopoly market. The telcos have a monopoly so they can make you pay big bucks for an over-engineered network. But in a free market situation, the tier 1 NSP's, the tier 2 RNP's (Regional Network Providers) and the ISP's at tier 3 only add capacity when customers are ready to order and pay for that capacity. This is good because it keeps prices under control and relatively flat rate. J) All his 1, 2, 3, 4 points about Cisco routers are either wrong, minor problems, or things that have been fixed. K) Last year people though collapse was imminent when NSFnet shut down. But when it actually happened nobody noticed because everything worked fine. Later on, however, problems started to appear with route announcements as more ISP's started to use the BGP routing protocol but some smart engineer invented route dampening and Cisco promptly implemented it and the problem was promptly solved just in time. Kind of like things normally work in a free market -- see point I above. L) Of the three URL's given, two are wrong. One should be www.ietf.cnri.reston.va.us and the other should be www.internic.net. Actually, www.ietf.org is easier to remember. Besides, I don't see what any of those URL's has to do with router shutdowns (rare) and Internet slowdowns. M) Now we have a garbled comment about Cisco routers that imply they are broken. In actual fact most tier 1 NSP's use Cisco routers because they are the only ones that can handle the complex mesh of the global Internet core and the traffic load at the core. N) Some mythical NANOG study is quoted to make some point or other which makes no sense to me. Obviously some reporter looked in on a bunch of network engineers talking about stuff that he doesn't understand and jumped to conclusions. I suppose he would be upset if somebody showed him that there was grease on the engine under the hood of his car! The real world is *NOT* seamless and sweet. There are real people, mechanics, engineers, etc, that make things works and deal with the grungy mess that underlies 100% of modern technical society. If you can't handle this, don't peek under the hood! O) I suppose I better deal with the specifics rather than just the generalities here. In this quote "A problem that Cisco routers have with the Internet Protocol itself is causing router update oscillation, link/router failures and congestion." it appears that Cisco routers have a fundamental flaw at the IP level. However the mention of router updates seems to point at BGP which is a higher level protocol. Sounds like yet another rehash of the BGP dampening code. In any case the important thing here is that engineers are studying what happens, discovering some things that don't work well, pinpointing why they don't work well, and *FIXING* them. Give the engineers a round of applause for discussing this in the open at NANOG instead of hiding it all behind a veil of secrecy. P) Two more URL's. One so general I don't see the point. The other one is broken. Don't these writers even use the Internet? Q) The column talks about Sprint's route filters as if they target small ISP's when in reality they target small networks who also have the mistaken idea that they can bypass the address allocation hierarchy and still get working addresses. Then it talks about address crowding which has nothing whatsoever to do with Sprint's filters. The filters are there as part of the impetus to reduce the size of the global routing table so it is not filled with garbage like this: 208.10.16/24 Fred's ISP --> send to Big ISP 208.10.17/24 Widget World --> send to Big ISP 208.10.18/24 Malls Electric --> send to Big ISP 208.10.19/24 Billy's BBS --> send to Big ISP Instead it should look like this 208.10.16/22 Some BIG ISP customers --> send to Big ISP which takes up less global routing table space and still gets the traffic where it is supposed to go. R) The columnist does not explain that Sean Doran's quote applies to the larger ISP's who are the ones running BGP and who should be controlling their routes so that they do *NOT* flap. It is punishing poorly run large ISP's and not small ISP's. S) It seems that Sprintlink customers are treated more leniently. So what, they pay Sprint for the service, don't they? If even one other tier 1 NSP implemented the same policy as Sprint then Sprint's lawyers (who wrote their customer contracts) would have the excuse they need to apply the same policy to Sprintlink customers. T) The columnist mistakenly refers to Yakhov Rekhter as "Cisco Systems'" whereas in fact IETF members *NEVER* represent the sompany they happen to work for at the time but only represent themselves. U) The hierarchical IP numbering scheme being discussed is in fact the scheme in place today and it has been so for some time. The IETF and IANA merely want to document this scheme and clarify it by publishing a Best Common Practices RFC so that it is easier for everybody to understand and explain what is going one. If this would cause you hardship, tough bananas! That's life. This is how things are in order to make the Internet operate effectively and if you didn't know this and make engineering and business plans accordingly then that's your problem. But it's never too late to educate yourself and to adjust your engineering and your policies to lessen the negative impact of hierarchical addressing. V) All this talk about fees for routes is just that. Talk. There isn't even an IETF working group yet for this topic but if you are real interested you can join piara@apnic.net (get ready to be flamed to a crisp if you ask dumb questions on this list) or better yet hunt up the PIARA mailing list archives at ftp.apnic.net I believe. W) This thing about "large providers blame small ISP's" is ludicrous. It's true that some few employees of large ISP's say nasty things about small ISP's but so what. The small ISP's who are clueless and do stupid things deserve to have nasty things said about them. There is such a wealth of educational material on the Internet about how to run an ISP and how to run a network that there really should not be any clueless small ISP's. Unless, of course, they think that $9.95 per month all you can eat service is the road to riches :-( X) I'm not going to say much more about all this talk of mythical charges. Just be aware that anyone can say what they want but that does not mean it will happen. But do pay attention to the cost of renumbering. If you do not plan your network and your business from day 1 with renumbering in mind then it will hurt bad when you have to do it and it could kill your business. Be prepared. Y) This idea of ISP co-ops is sort of what a tier 2 Regional Network provider does. If you are a customer of Netaxs or TLG or IXA then not only are you somewhat insulated from a lot of these problems but you have a certain ammount of access to some very skilled people who can help you make sure your networks are properly designed and configured. Z) There is no power in owning IP address blocks because at the present time IP addresses are not owned. Right now the power is in having a *WORKING* IP address block and that is intimately tied in to your choice of upstream provider. And if you change providers then you will have to change IP address blocks in order to retain that power of having a working address. *sigh* That guy gets paid for writing his confusing mish-mash of a column and I get paid nothing for writing this explanation which I have gone to some trouble in making as accurate as possible. Michael Dillon - ISP & Internet Consulting Memra Software Inc. - Fax: +1-604-546-3049 http://www.memra.com - E-mail: michael@memra.com