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Re: GSR and bgp maximum-paths
by Paul Froutan 06 Mar '01

06 Mar '01

At 3/6/01, James DeMong wrote: >Long time listener, first time caller. > >I would like to enable multipath bgp on a GSR running 12.0(10)S that has two >bgp neighbors in the same AS connected via OC-3 pos in order to load balance >outbound traffic across the two pos connections. > >I've checked out the cisco bug search and haven't found any for this feature >on this release of IOS. > >Is anyone else have any problems with "maximum-paths" on a GSR and if yes, >what release of IOS? Any other issues I should be aware of? We used to run that with a couple of DS-3s and didn't have any issues. ---------------------------------------------------------------------- Paul Froutan Email: pfroutan(a)rackspace.com Rackspace Managed Hosting <http://www.rackspace.com>

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Re: Linux clusters?
by David Lesher 06 Mar '01

06 Mar '01

You might look at Scyld.com as rumor has it the folks there know a little bit about Linux clusters. -- A host is a host from coast to coast.................wb8foz(a)nrk.com & no one will talk to a host that's close........[v].(301) 56-LINUX Unless the host (that isn't close).........................pob 1433 is busy, hung or dead....................................20915-1433

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RE: Network Sizing Guidelines?
by Irwin Lazar 06 Mar '01

06 Mar '01

I'd recommend taking a look at: Wide-Area Data Network Performance Engineering By Cole, Robert G. / Ramaswamy, Ravi ISBN: 0890065691 Here is a guideline based on Ravi's methodology that I wrote for our customer newsletter some time ago: The bandwidth size that is required for any given connection is a function of the following three factors, number of users, requirements of specific applications, and how the application is used. For example, a site with five users that all access a highly interactive application for twelve hours per day may require more bandwidth than a site in which a dozen users sporadically access a client-server application in which most of the processing is performed by the remote server. In addition, another concern in the bandwidth selection process is delay. Certain applications such as voice and video may require a low level of delay (latency) as well as a low variability in delay (jitter). These requirements may add significant complexity to the design process. The first step in sizing bandwidth is to determine the requirements for the specific applications that will be deployed. During this step, a sniffer is useful in tracing application sessions to determine the average packet size and the average number of packets for a given transaction. Once you have these values, the next step is to factor in the number of users, the required latency, and the amount of time that typically exists between transactions. Once you have obtained these values, you can use the following formula (created by Ravi Ramaswamy of AT&T Solutions) to determine bandwidth requirements: 8 x N x K x M / (K x P + T) Where: N = number of active users at a location (the number of users that will simultaneously use an application) T = User think time (how much time typically exists between inquiries K = number of packets per transaction in any given direction M = number of bytes per packet in any one direction P = one-way network latency Note that this calculation must be performed for both directions of the connection. The required bandwidth is then the maximum bandwidth estimated by this formula (unless you are deploying a technology such as Frame Relay which allows for different bandwidth allocations for each direction of the connection). Note also that this formula only applies to client-server type applications in which there is a substantial amount of two-way traffic. For additional information on bandwidth sizing, please see "Optimizing Client-Server Application Performance on the WAN" in the November issue of "Network Magazine." ----- Irwin Lazar - ilazar(a)tbg.com <mailto:ilazar@tbg.com> Senior Consultant, The Burton Group Office: 703-742-9659 Cell: 703-402-4119 http://www.tbg.com/ "The Ultimate Resource For Network Architects" -----Original Message----- From: Daniel R Glover [mailto:Daniel.R.Glover@grc.nasa.gov] Sent: Friday, March 02, 2001 5:00 PM To: nanog(a)merit.org Subject: Network Sizing Guidelines? Can you point me to some current network sizing advice for Internet service (WAN and LAN)? I am looking for rules-of-thumb, guidelines, equations, books, or even anecdotal evidence that would help me in evaluating future network design concepts. I have somewhat unconventional network constraints, but I would like to start from current conventional assumptions on, say, numbers of users (home or office) that can be supported by various bandwidths. I've tried the related links off the NANOG pages, but some are old or broken. I have found some advice like "a T1 will support 200 to 300 28K modem users," but I hope there may be more current advice somewhere especially with regard to QoS, future trends, and to larger networks. Any relevant pointers or advice would be welcome. R/ Dan Glover

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Linux clusters?
by Ben Browning 06 Mar '01

06 Mar '01

I am looking for a few good resources on building Linux clusters to serve as mail farms. Specifically, books. Ordinarily I would turn to O'Reilly, but "Building Linux Clusters" is out of print due to bad response (per http://www.oreilly.com/catalog/clusterlinux/ ). Any suggestions would be highly appreciated in private email, so as not to spam the list. Thanks! --- Ben Browning <benb(a)theriver.com> The River Internet Access Co. Network Operations 1-877-88-RIVER http://www.theriver.com

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ibm.net mailservers gone
by Roy 06 Mar '01

06 Mar '01

I have been told that the ibm.net mail servers are now "officially" closed. The MX records are gone and the "A" record points to a server that does not have anything running on port 25. Roy Engehausen

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Resource for determining lit buildings
by Doane, Andrew 05 Mar '01

05 Mar '01

Anyone know of an online resource for checking facilities/providers by building address? Is it on-net, is it Sonet, that type of thing. Thanks, Andrew -- Andrew J. Doane Dotspot, Inc. v:630.799.7500 x33913, f:240.337.2349 e:andrew.doane@dotspot.com p:1161673@skytel.com

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Mcleod.net anyone?
by Sehmel, William C. 05 Mar '01

05 Mar '01

Has anyone ever delt with mcleod.net for connectivity before? They gave us a pretty nice offer, just wanted to get info from other people on them. Please reply off list Thanks Bill Sehmel Sr. Network Engineer chcs.com wcs(a)chcs.com "The great nations have always acted like gangsters and the small nations like prostitutes." -- Stanley Kubrick

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Network Sizing Guidelines?
by Daniel R Glover 05 Mar '01

05 Mar '01

Can you point me to some current network sizing advice for Internet service (WAN and LAN)? I am looking for rules-of-thumb, guidelines, equations, books, or even anecdotal evidence that would help me in evaluating future network design concepts. I have somewhat unconventional network constraints, but I would like to start from current conventional assumptions on, say, numbers of users (home or office) that can be supported by various bandwidths. I've tried the related links off the NANOG pages, but some are old or broken. I have found some advice like "a T1 will support 200 to 300 28K modem users," but I hope there may be more current advice somewhere especially with regard to QoS, future trends, and to larger networks. Any relevant pointers or advice would be welcome. R/ Dan Glover

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Re: Covad SUCKS!
by Sam Habash 05 Mar '01

05 Mar '01

On Wed, 28 Feb 2001, Adam McKenna wrote: > Hmm, gee, isn't there a cliche' that fits this exact problem? Something > about eggs? Yeah, all of MHSC.COM dns is fried in one swamp /24-sized basket: NS1.MHSC.NET 199.108.175.25 NS2.MHSC.NET 199.108.175.27 NS3.MHSC.NET 199.108.175.26 --Sam

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RE: Network Sizing Guidelines? [OT]
by Mathew Butler 04 Mar '01

04 Mar '01

May you live in interesting times, may you get everything you ask for, and may you come to the attention of those in power. - Ancient Chinese Proverb Mat Butler -----Original Message----- From: Valdis.Kletnieks(a)vt.edu [mailto:Valdis.Kletnieks@vt.edu] Sent: Saturday, March 03, 2001 9:08 PM To: Scott Francis Cc: nanog(a)merit.org Subject: Re: Network Sizing Guidelines? On Fri, 02 Mar 2001 16:40:27 PST, Scott Francis said: > Freenet, Gnutella, Aimster ... napster is merely the poster child for a > new generation of file sharing clients and protocols. Pandora has > already opened the box, regardless of Napster's ultimate fate. I'm not sure which is more surreal, the 11th-hour proposal by Napster to filter based on filename "because nobody would ever misspell Metallica", or the interesting twist in Aimster's usage policy, which would require the record industry to intentionally violate the same laws they wanted passed in order to get evidence to use as the basis of a lawsuit.... "There is a theory which states that if ever anyone discovers what the Universe is for and why it is here, it will instantly dissapear and be replaced by something even more bizzare and inexplicable. There is another that says this has already happened". -- Douglas Adams "May you live in interesting times" -- ancient Chinese curse Hang on everybody, we're in for a ride.... Valdis Kletnieks Operating Systems Analyst Virginia Tech

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