December 2003 - NANOG - lists.nanog.org

RE: MTU path discovery and IPSec
by cproctor＠epik.net 10 Dec '03

10 Dec '03

The problem is described pretty clearly at http://www.cisco.com/warp/public/105/56.html. The issue I have experienced is that fragmentation can lead to performance impacts that are unacceptable. I wish we could start a clue campaign informing people why ICMP should not be summarily dumped at the firewall. Chris Proctor EPIK Communications > -----Original Message----- > From: Valdis.Kletnieks(a)vt.edu [mailto:Valdis.Kletnieks@vt.edu] > Sent: Wednesday, December 03, 2003 11:39 AM > To: jgraun(a)comcast.net > Cc: nanog(a)merit.edu > Subject: Re: MTU path discovery and IPSec > > On Wed, 03 Dec 2003 16:05:39 GMT, jgraun(a)comcast.net said: > > > 1) I assume MTU path discovery has to been in enabled on > each router in the path in order for it work correctly?! > > Actually, no. All that's required is that: > > a) The router handle the case of a too-large packet with the > DF bit set by > sending back an ICMP 'Dest Unreachable - Frag Needed' packet. > I've never > actually encountered a router that didn't get this part > right. (Has anybody ever > seen a router botch this, *other* than a config error covered > in (b) below?) > > b) said ICMP makes it back to the originating machine. This > is where all the > operational breakage I've ever seen on PMTU Discovery comes > from. And in almost > all cases, one of two things is at fault. Either some > bonehead firewall admin > is "blocking all ICMP for security" (fixable by reconfiguring > the firewall to > let ICMP Frag Needed error messages through), or some > bonehead network provider > numbered their point-to-points from 1918 space and the ICMP > gets ingress/egress > filtered (this one is usually not fixable except with a baseball bat). > >

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Re: Authority (fwd)
by Owen DeLong 10 Dec '03

10 Dec '03

I apologize for further troll feeding, but, I think this warrants some clarification... > I take issue with anyone who publicly accuses another entity of wrongdoing > beyond his scope of authority. > You can take issue, but, there is no scope of authority for accusations. Anyone can make an accusation against anyone else at any time. At least in the united States. It's part of what is known as free speech. > If people are speeding in my neighborhood, I can not go and take down > their pictures, personal information, license plate numbers, etc., post > them pupubliclyand accuse them of breaking the law (even if they did!). > That's liabel, and it is illegal (and wrong). It is no less wrong just > because it is up to the victim of the post to take corrective/punative > action in a civil forum (ie lawsuit). > Actually, you can. There is no law against it. The word you were looking for is Libel, not Liabel, and, for a claim to be libelous, it must meet the following criteria: 1. It must be published 2. It must be provably false 3. It must cause harm Legally, you can take pictures of anything in a public place and publish them. Legally, you can write down a license number observed in a public place. Further, unless the person can claim that your statement they were speeding is false by preponderance of the evidence, they are unlikely to succeed in suing you for libel. You can take issue with it all you want. Whether it is right or wrong to do so is a separate issue. However, it is most definitely _NOT_ illegal at least not under the libel laws. > The correct action would be to lobby the authorities (police in the > example, arin in this situation) to take enforcement measures, NOT to > demand that the "criminals" justify their actions to you (specifically > speaking to whom my email was originally addressed). There are fiscal and > legal ramifications to what is being done here. > I suggest you do some further study before making legal claims. What you have done here is merely demonstrate an ignorance of the law. I don't always agree with William, but, I haven't seen him do anything illegal yet. Owen -- If it wasn't crypto-signed, it probably didn't come from me.

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4.5 magnitude earthquake in VA
by JC Dill 10 Dec '03

10 Dec '03

http://earthquake.usgs.gov/recenteqsww/Quakes/uscdbf.htm

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RFC2544 Network Benchmark Testing
by Stephen Perciballi 09 Dec '03

09 Dec '03

Hi, Does anyone have or know of any open source software for RFC2544 testing? IXIA boxes are nice but I don't plan on buying one right now. All other tools I've looked at seem to be lacking in one way or another. They have been really good at flooding the link ~or~ setting frame sizes etc. Any help would be appreciated. -- Stephen (routerg) irc.dks.ca

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Re: Evolution of the U.S. Peering Ecosystem v1.1
by William B. Norton 09 Dec '03

09 Dec '03

At 06:23 PM 12/5/2003 -0500, alex(a)pilosoft.com wrote: > > 1) The Cable companies are peering (with Tier 2s and each other) in a > > *big* way >That's probably why ATDN depeered ~20 networks over last few months, >while Comcast and Charter do not peer at all. I had not heard that. As for Comcast and Charter, I would add the word "yet." > > 2) The Large Network Savvy Content Companies are getting into peering in > > a *big* way >With transit bandwidth at 20k$/GE, and Equinix shared fabric now priced at >nearly half that, I don't see that many "content companies" peering all >that much. The phrase, "You get what you pay for" comes to mind. There is real difference between transit services IMHO. Also, you rarely use the full gigE in these types of arrangements, so you need to be a little careful doing the "simple math." Having said all that, the transit price pressures are certainly there and it does make the peering financial argument a little tougher. I've heard the argument that "Peering is better than transit. It ought to cost more." > > 3) The Large Network Savvy Content Companies are getting their content > > directly onto the Cable companies eyeball networks by peering > > relationships. >I wish. Well then you shall receive. The large guys do peer (Yahoo!, MSN, Google, EA, Sony Online, etc.) in a very big way. I expect too these guys are simply leading the charge - those content companies large enough to employ a network engineering staff that can do the math will be following as well. It is not only a financial motivation; peering provides greater control over routing and is often seen as a performance enhancing strategy. Folks like Yahoo! seem to emphasize the end-user performance improvements over the financial savings these days. >Out of big eyeball networks, only SBC has reasonably open policy, rest are >attempting to force "content networks" into paid peering arrangements >using restrictive ratio requirements Hmm. SBC has what I call a "Selective Peering" inclination; they will peer with you if you meet certain criteria. The cable companies are all different of course but generally seem to have migrated from a "No Peering" inclination (when @Home ran things for them the cable companies didn't peer) to an "Open Peering" inclination to reduce costs (and to deal with Kazaa traffic), to a "Selective Peering" inclination. I see this last step as an operations sanity motivation; peer with those who have at least 10M of traffic to exchange on a couple coasts. If you don't have that much traffic it may not be worth the time to configure the session, and when things break it may be more hassle than it is worth. The ones who are a bit different are the "Restrictive Peering Inclination" folks; those who have a peering policy articulated solely so they can say "No" with a reason. Rather than deal with the hassle of peering requests, some of these guys don't articulate their Peering Inclination in the form of a Peering Policy. "We have all the peering that we need" is the attitude, and, not to open a can of worms here, but it is a business rational attitude. Bill >-- >Alex Pilosov | DSL, Colocation, Hosting Services >President | alex(a)pilosoft.com (800) 710-7031 >Pilosoft, Inc. | http://www.pilosoft.com

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tracking down subnet announcement disappearing / dropping to a single provider
by Eric Kagan 08 Dec '03

08 Dec '03

I apologize if this is off-topic - I rarely post, mostly just monitor. I am not posting this to [nsp] or [isp-bgp] for I don't believe the following is a configuration problem on my side, but an operational one of a certain provider. I am not going to sling dirt or put actual names / ASN, etc for now. I want to list the problem and if it is relevent I can post more specific data or be contacted offlist with suggestions or from the provider. The problem is completely intermittent. 99% of the time everything works fine. I have begged the customer to get their ASP's ISP involved since I believe that is where the problem lies. They claim it is my problem since we connect to them.....(Don't want to start a war here...I know) I am Provider A and my customer cannot connect to an ASP through Provider X. The problem lasts for what seems to be exactly 10, 15 or 30 minute intervals. I am announcing my /19 broken up into multiple /22 and /21's. It is only 1 of the /22 that has the problem. One of my links is not going down and I do back backup routes through multiple providers. It took me almost a month to confirm the problem because they would call be *after* it happened and everything would look fine. I put some monitors on the destination site and it will never test bad since the monitors were on other subnets. They finally called me while it was occuring and I did confirm I could not reach the site from any of the IP's in that certain /22 subnet. So, my point and questions: Has anyone ever heard of such a problem ? I tried to search some archives and google - but I can't really figure out what to search on that won't result in 1000 + matches. Is there any function or problem that might exist for exactly 10, 15 or 30 minutes (i.e. BGP Flap, subnet block filter / ACL ?) over and over ? Should I contact provider X dircectly ? Will they work directly with me ? I believe my customers ASP opened a ticket with their ISP but with all the layers and short time frame of the issue I don't think it will get resolved quickly or easily. Responses online or offline welcome. If anyone wants more specific info posted to the forum (IP subnet blocks, Provider X, ASN, etc) please let me know. Thanks Eric Eric Kagan Commrail, Inc. dba Access Northeast support(a)axsne.com 978-562-4475

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Re: Cisco GSR logging issue
by Richard Welty 08 Dec '03

08 Dec '03

just a quick note to say thanks to those who have responded, off list and on. i've got some useful stuff, but haven't had time to sort through and reply to everything. i'll likely be putting up a web site on "safe" ways to configure logging on various types of routers so that you can trap the data needed for AUP/TOS enforcement against proxy hijackers and other network abusers w/o accidentally bringing down your network. richard -- Richard Welty rwelty(a)averillpark.net Averill Park Networking 518-573-7592 Java, PHP, PostgreSQL, Unix, Linux, IP Network Engineering, Security

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Re: Need Contact at RoadRunner
by Michael.Dillon＠radianz.com 08 Dec '03

08 Dec '03

>Unless you like playing whack-a-mole, you need a smarter hammer, not a >bigger one. Email peering *IS* a smarter hammer. If all the cluefull email administrators would set up peering agreements with each other and exchange contact information, there would be fewer of these situations. Part of the problem is that there are no agreed rules of engagement for email abuse issues. By setting up email peering agreements in advance, we could put those rules of engagement in place and we could ensure that our email peers have the *RIGHT* contact information. Domain registry whois listings and INOC-DBA are not the right contact information because they are too general. Now, an email peering agreement could very well specify that certain whois contact listings should be used as a second resort and that agreement would make them the right contact info. Also, the email peering agreement could specify that INOC-DBA phone number ASNUM*999 is the number one choice of contact method and then it would become the right way to contact email peers. The fundamental problem is not that there isn't technology in place to solve these problems; it is that there aren't *AGREEMENTS* in place to solve these problems. Organizations like CAUCE are happy to just bitch and moan instead of working to bring all email operators together to set up working agreements for *MANAGING* the email abuse problems instead of always letting the abusers take the first steps and drive the whole issue. Anyone for a joint NANOG/CAUCE meeting? http://www.cauce.org In fact, given the past experience with two joint ARIN/NANOG meetings could the best way forward be to have more joint meetings that combine a NANOG meeting with some other non-BGP/routing operational forum? Perhaps something jointly with a security organization like CIS? http://www.cisecurity.org/ Suggestions? --Michael Dillon

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Cisco GSR logging issue
by Richard Welty 08 Dec '03

08 Dec '03

i'm working with some folks to try and develop evidence about proxy hijackers on or transiting their networks. i have useful notes about doing this with non-GSR Cisco routers, but right at the moment all i have for the GSRs is a note indicating that netflow is needed. i have no personal experience with the GSRs and am looking for one of two things: 1) someone experienced in capturing this stuff on a GSR or 2) a pointer to a cisco oriented list where i can get 1) above. thanks in advance, richard -- Richard Welty rwelty(a)averillpark.net Averill Park Networking 518-573-7592 Java, PHP, PostgreSQL, Unix, Linux, IP Network Engineering, Security

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Re: Router with 2 (or more) interfaces in same network
by Rosen Adam J NPRI 08 Dec '03

08 Dec '03

Hi. This topic was discussed about a month ago, but I just found this mail list while doing a search. I have the same question that was discussed before. However, this is the first router I have ever set up, so I could be completely wrong about how I am doing things, but I'll explain to the best of my ability. I am setting up a router/firewall (Nokia IP380). For redundancy, I want 2 interfaces on the same subnet. The IP380 will be connecting to a pair of routing switches which are running VRRP. I am trying to use static routes, due to the fact that network topology will not be changing outside of hardware failure, and to keep speed as high as possible. How can I set up static routing to the virtual router if I can't have a second interface on the same subnet to pick up the floating IP address in case the VRRP master fails? Am I misunderstanding VRRP here? If anyone can give me some helpful hints, I would appreciate it. Thanks Adam Adam J. Rosen Code 2233 Naval Undersea Warfare Center 1176 Howell St. Bldg. 1171-2 Newport, RI 02841 Phone: 401-832-4740 Toll Free: 800-669-6892 x24740 Fax: 401-832-2130 Email: rosenaj(a)npt.nuwc.navy.mil

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