August 1995 - Test - lists.nanog.org

Re> Re: ATM thruput
by Dave Reese 10 Aug '95

10 Aug '95

Sean, Actually we are experimenting with ATM, and have been for about 12 months now. We have 5 sites throughout California inter-connected with ATM for distance education projects and we are now expanding this trial to include IP traffic. Three more sites will be added soon. We are using NewBridge 36150 ATM switches with their JPEG video cards to provide VCR-quality full motion two-way video for the Library Sciences Masters Degree program between Northern and Southern California. At CSU, Hayward there is a scanning electron microscope which broadcasts its images through this network as well. The microscope can be controlled remotely at the viewing site through IP access. We recently added ATM/OC-3 processors to our cisco 7000 series routers to provide IP access. SGI workstations and servers with ATM NIC cards are interconnected to the cisco and NewBridge equipment through FORE switches at some of the sites. Thank you for your inquiry, Dave Reese Director, Networking & Computing Services California State University ------ From: Sean Doran, Thu, Aug 10, 1995 ------ [quoting entire message] >d Hm, been experimenting with ATM at CalState again, eh? Sean. ------------------ RFC822 Header Follows ------------------ Received: by ml.calstate.edu with SMTP;10 Aug 1995 16:08:05 -0700 Received: by calstate.edu (5.57/Ultrix-4.1/CSUnet 1.2) id AA03753; Thu, 10 Aug 95 16:08:02 -0700 Received: from cesium.clock.org (cesium.clock.org [17.255.4.43]) by merit.edu (8.6.12/merit-2.0) with SMTP id SAA15353 for <nanog(a)merit.edu>; Thu, 10 Aug 1995 18:11:53 -0400 Received: by cesium.clock.org id <5811>; Thu, 10 Aug 1995 15:11:31 -0700 From: Sean Doran <smd(a)cesium.clock.org> To: dsiegel(a)net99.net, jim(a)calstate.edu Subject: Re: ATM thruput Cc: nanog(a)merit.edu, pushp(a)cerf.net Message-Id: <95Aug10.151131pdt.5811(a)cesium.clock.org> Date: Thu, 10 Aug 1995 15:11:27 -0700

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Re: ATM thruput
by Sean Doran 10 Aug '95

10 Aug '95

[quoting entire message] >d Hm, been experimenting with ATM at CalState again, eh? Sean.

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CERT Vendor-Initiated Bulletin VB-95:06 - Cisco
by CERT Bulletin 10 Aug '95

10 Aug '95

CERT Vendor-Initiated Bulletin VB-95:06 August 10, 1995 Topic: Vulnerability in Cisco's IOS software Source: Cisco Systems To aid in the wide distribution of essential security information, the CERT Coordination Center is forwarding the following information from Cisco Systems. NOTE THAT THIS IS NOT NEW INFORMATION; CISCO RELEASED THIS ADVISORY TO THE PUBLIC IN JUNE 1995. If you have already seen this and are certain that you have correctly configured your routers, you do not need to take any further action. However, if you have not seen this Cisco Security Advisory or are not certain that your routers are configured correctly, we urge you to review this bulletin and check the configuration of your router. Cisco contact information is included in the forwarded text below; please contact them if you have any questions or need further information. ========================FORWARDED TEXT STARTS HERE============================ Cisco Security Advisory Thu Jun 1 16:27:08 PDT 1995 ------------------------------------------------------------------------------ The following describes a vulnerability in Cisco's IOS software when the 'established' keyword is used in extended IP access control lists. This bug can, under very specific circumstances and only with certain IP host implementations, allow unauthorized packets to circumvent a filtering router. This vulnerability is present in the following IOS software versions: 10.3(1) through 10.3(2) 10.2(1) through 10.2(5) 10.0(1) through 10.0(9) ...and all previous versions of Cisco software. If you are running any of these IOS versions on a product that uses IP extended access lists, and you are using the 'established' keyword in these lists, then Cisco strongly recommends that you take immediate action to remove the vulnerability. You can determine what version of IOS you are running by issuing the following command: show version The recommended action is to upgrade to a more recent version of IOS, or take one of the immediate workaround actions described below. The vulnerability is fixed by in the following official software releases: 10.0(10) or later 10.2(6) or later 10.3(3) or later (For reference, the Cisco update identifier for this fix is "CSCdi34061".) Customers may obtain software upgrades without going through the Cisco's Technical Assistance Center (TAC) via the Cisco Information Online (CIO) service. Instructions for downloading are available at the end of this message. You may also contact your Cisco distributor or contact Cisco's TAC for more information. The TAC can be reached by phone at 800-553-2447, by e-Mail at tac(a)cisco.com or via the World Wide Web at http://www.cisco.com (for registered CIO users only). In Europe, you can contact the TAC by phone at 32-2-778-42-42 or via e-Mail to euro-tac(a)cisco.com. ------------------------------------------------------------------------------ Details 1. Description A bug in Cisco's extended IP access list implementation can, under very specific circumstances, allow a user to bypass IP packet filtering. This may permit unintended IP traffic to pass through your firewall setup. To determine if you are vulnerable, look through your configuration. The configuration can be displayed by enabling and then entering the command "write term". If you see an access list line using a list number in the range of 100 through 199 that permits or denies TCP traffic and contains the word 'established' near the end of the line, you may be vulnerable. An example line might look like: In IOS 10.3: access-list 100 permit tcp any any established In IOS 10.2 or earlier: access-list 100 permit tcp 0.0.0.0 255.255.255.255 0.0.0.0 255.255.255.255 established If you do not meet this test, then you are not vulnerable. You do not need to do anything. 2. Workaround The following actions will remove the vulnerability: o Rewrite the access list parameters so the 'established' keyword is not necessary. This does not simply mean that you may remove the 'established' keyword, but rather that you will need to re-design your access lists to provide similar functionality without using the established mechanism. or o Disable the interfaces to which the access list is applied using the 'shutdown' interface subcommand. Example: router(config)#interface ethernet 0 router(config-if)#shutdown 3. Solution Obtain and install the appropriate release of IOS software as described above. For assistance, contact Cisco's TAC. 4. Technical Comments This problem is caused by an obscure but common design flaw that we believe exists in many router/firewall vendor's packet filtering implementations. Owners of non-Cisco hardware who use IP packet filtering features similar to Cisco's "extended access lists" as part of a firewall system may wish to contact their vendor to confirm that this vulnerability does not exist in their system. (Technical discussions about the problem have already occurred in the appropriate forum.) This vulnerability can only be exploited with certain IP host implementations (we do not have information on which implementations are susceptible). Cisco suggests that all routers configured to filter IP packets based upon the 'established' mechanism be upgraded. ------------------------------------------------------------------------------ Software Upgrades Software upgrades may be obtained via any of the following mechanisms: * World Wide Web (WWW): For registered CIO users please open a URL to: http://cio.cisco.com/kobayashi/Library_root.shtml and select the version of software to download. For non-registered users open a URL to: http://cio.cisco.com/public/library/spc_req.shtml When prompted for a code, please enter: certjun2 for a list of available files to download. * FTP: ftp cio.cisco.com and at the initial (username) prompt, enter: certjun2 At the password prompt, enter your e-mail address. Then: get README.certjun2 This file contains a list of files available that close this vulnerability. Please examine this list to determine which files you need and then download them. * Character-based "CIO Classic": For access, the following connection options are offered: o telnet: cio.cisco.com o Dial-up modem: In Europe: +33 1 64 46 40 82 In the US: (408) 526 8070 Settings: vt100, N81, up to 14.4Kbps Enter either as a guest or registered user and navigate to the topic: Software Updates Special Files At the prompt for a code, please enter: certjun2 A list of files will be displayed for you to select and download. ------------------------------------------------------------------------------ =========================FORWARDED TEXT ENDS HERE============================= CERT publications, information about FIRST representatives, and other information related to computer security are available for anonymous FTP from info.cert.org. CERT advisories and bulletins are also posted on the USENET newsgroup comp.security.announce. If you would like to have future advisories and bulletins mailed to you or to a mail exploder at your site, please send mail to cert-advisory-request(a)cert.org. If you wish to send sensitive incident or vulnerability information to CERT staff by electronic mail, we strongly advise that the e-mail be encrypted. The CERT Coordination Center can support a shared DES key, PGP (public key available via anonymous FTP on info.cert.org) or PEM (contact CERT staff for details). Internet email: cert(a)cert.org Telephone: +1 412-268-7090 (24-hour hotline) CERT personnel answer 8:30 a.m.-5:00 p.m. EST(GMT-5)/EDT(GMT-4), and are on call for emergencies during other hours. Fax: +1 412-268-6989 CERT Coordination Center Software Engineering Institute Carnegie Mellon University Pittsburgh, PA 15213-3890 USA CERT is a service mark of Carnegie Mellon University.

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Re: ATM thruput
by jim＠calstate.edu 10 Aug '95

10 Aug '95

d

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Re: routing meltdown - let's talk at Pittsburgh
by sob＠academ.com 09 Aug '95

09 Aug '95

Okey, I'd be happy to take this one on. Does anyone have an objection to the agenda sequece that Curtis suggested in his earlier mail? Are they any additions or sequence changes that folks want to suggest? Finally, since I am not dexterous enough to takes notes ANY moderate, are there any volunteers to take notes? [Note: Yes, I am once again volunteering to be the note taker for NANOG unless someone else wants to do it. I have been kinda busy in the last few months and have not had a chance to get all the materials into the last set of pages I built. I am committed to getting that done before the September NANOG, though.] -- Stan | Academ Consulting Services |internet: sob(a)academ.com Olan | For more info on academ, see this |uucp: amdahl!academ!sob Barber | URL- http://www.academ.com/academ |Opinions expressed are only mine.

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Re: routing meltdown - let's talk at Pittsburgh
by sob＠academ.com 09 Aug '95

09 Aug '95

Curtis, I'd be willing to proxy-moderate if you can't get an asbestos suit. I think this is an important issue and certainly should be discussed at NANOG. -- Stan | Academ Consulting Services |internet: sob(a)academ.com Olan | For more info on academ, see this |uucp: amdahl!academ!sob Barber | URL- http://www.academ.com/academ |Opinions expressed are only mine.

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Re: routing meltdown - let's talk at Pittsburgh
by Sean Doran 09 Aug '95

09 Aug '95

I'll be prepared to talk about it, but I like your offer of proxy-moderation. I always seem to end up either lecturing or playing Phil Donohue. Sean.

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routing meltdown - let's talk at Pittsburgh
by Curtis Villamizar 09 Aug '95

09 Aug '95

Sean, Could you please sign up to lead a discussion of the impending routing meltdown as you see it at the upcoming NANOG meeting. You've been very vocal on CIDRD, but it is not clear what solutions you are offering. I sincerely would like to know what you feel the problem is (though I have a good handle on this part already, I think) and what could be done about it. Specifically (for discussion at the meeting): 1. Number of destinations - 30K one path is beyond the technology available today, but it is pushing what parts of the Internet can support. Right? CIDRization helps here (and in 2 and 3 below). How can we better promote CIDRization? Can we do a better job of identifying who still needs to CIDRize? Are we ready to do proxy aggregation, and if so on what scale? Under what circumstances is hostile proxy aggregation (without the approval of the originator of the routes) justified? What safeguards should be in place to prevent hostile aggregation with no approval whatsoever? Or should the ability to do hostile aggregation be a feature??? 2. Number of paths - what is the limit on paths 100k, 200k? Are there ways to reduce the number of paths at hot spot routers? a. If the hot spot routers are at the exchanges and the problems are too many peers would it help to take routing from a single third party like a route server? Is there something wrong with the route server model, or the people running the route server? (save RA flames for the meeting please!) b. If the problem is peering at too many exchange points with the same people, would it help to limit your peerings with other major providers to three or even two exchange points? This would need to be configured, so would some sort of registry for this type of configuration help? 3. CPU load. Are the efforts of Cisco in implementing route flap dampenning paying off? If so, do we anticipate that this will solve the problem or just buy us time (at this point it may be very preliminary)? Will the RA RS support dampenning? If you prefer, I will ask ANS to rent me an asbestos suit and I'll do my best to lead a discussion on this. This is just a suggested outline. If you want to lead the discussion, of course you are welcome to structure the discussion as you see fit. I'd like to hear your assessment of what the problems are and how you think the Internet community should be addressing them. There are people who claim that they are not opposed to the idea of documenting the routing topology to better coordinate routing configuration, particularly aggregation, but object to the way it is currently being done. I'd like to know how it could be better done. There is also the sticky issue of who will do it, whatever this better plan happens to be. Curtis

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Ideas for presentations
by Susan R. Harris 09 Aug '95

09 Aug '95

Greetings - Here are the presentations we've planned so far for the September 11-12 meeting: --Future of .COM and other top-level domains --NAP reports with focus on statistics being gathered --Route flapping update --RA status --SNMPv2 and next-generation network management tools Are there other topics you'd like to hear about? --Susan Harris

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route flap reports work now
by Curtis Villamizar 08 Aug '95

08 Aug '95

The good news is the the route flap reports are up again. The bad news for statistics fans is that while the reporting was down due to a disk crash, the machine that was thought to be still collecting raw data was switched to peer with a different router and was confused and declared all the BGP updates invalid for the entire (nearly a month) period. People with unstable routing signed up for the reports should start getting them again starting in an hour or less. Since my last message I got a lot of "what are these reports anyway" messages. Please see: ftp://ftp.ans.net/pub/info/routing-stats/daily-reports/README I just updated the README file a bit. For those that receive these, I'd like to take a poll. It appears that routing stability has improved since these reports first began. The previous criteria for reporting a network as "unstable" was 50 changes per day for a single prefix or a down time of 1 hour. I've just changed this to 20 changes and 15 minutes down time. I'd like to know if this is too sensitive after running for a while. Curtis

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