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Clueful comcast routing help needed, possible 69/8 filter issue?
by nanog 03 Jul '03

03 Jul '03

Looking for a Comcast/ATT network contact. I've gone through the published addresses and phone numbers, and noone seems to have a clue. There may be a 69/8 routing filter in place that that affects us in the dc area. thanks bill

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RE: RATE-Limiting and
by Vandy Hamidi 03 Jul '03

03 Jul '03

>From what I'm gathering, it's probably best to mark and police based on an access list similar to From Any to <web server> eq 80, or something to that effect. Maybe something like From <Firewal NAT IP> to Any eq any for internal users and police based on that. I don't think you can police based on individual flows that are defined by an aggregate ACL. So basically you can prevent public site traffic and Internal traffic from affecting each other, but not from affecting itself. An internal high-load user can slow down other users, but can be stopped from affecting web site performance. Scott M, do you think the Microflow policer you referred to can limit traffic based on individual flows within a defined range (acl)? -=Vandy=- -----Original Message----- From: Scott McGrath [mailto:mcgrath@fas.harvard.edu] Sent: Thursday, July 03, 2003 12:53 PM To: Vandy Hamidi Cc: Jack Bates; Andy Dills; prue; nanog(a)merit.edu Subject: Re: RATE-Limiting and Depends on the equipment you have installed. If you are running a 65xx/76xx if you are running mls with full flow masks you can set up a microflow policer which would allow you to mark or drop traffic on a per flow basis Scott C. McGrath On Thu, 3 Jul 2003, Vandy Hamidi wrote: > > Excellent point. It does depend on the traffic type. > Though I don't like to complicated my configs, you can always use CAR (cisco rate limiting) through an ACL to protect against the file transfer from the core servers issue you referred to below. It can make sure a high bandwidth xfer won't suck up all your available B/W. > > Does anyone out there know how to limit B/W based on Flow or individual sessions? Or even just source (where source is random). For example, a CAR where each IP source gets no more than X% of B/W (still allowing bursts if bandwidth is available). I think some QOS tagging and queuing would have to be involved. > > -=Vandy=- > > -----Original Message----- > From: Jack Bates [mailto:jbates@brightok.net] > Sent: Thursday, July 03, 2003 4:43 AM > To: Andy Dills > Cc: Vandy Hamidi; prue; nanog(a)merit.edu > Subject: Re: Newbie network upgrade question, apologies in advance to > NANOG > > > Andy Dills wrote: > > > > Yes, but the original poster was dealing with DS3s connected to different > > NAPs, which is why the packet out-of-order issue can be significant. > > > > I'd say that a more significant issue is customer throughput. The nice > aspect of per conn is that it not only tends to keep a decent load > balance, it also limits bandwidth hogs from saturating all circuits. > This of course depends on your desired result. An example in my case is > my helpdesk. They are off two t1's with dsl and dialup customers. I'd > prefer them not to tank both t1's when transfering files to and from the > core servers. > > -Jack >

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RE: National Do Not Call Registry has opened
by Callahan, Richard M, SOLGV 03 Jul '03

03 Jul '03

The FCC has, as of Thursday the 26th, adopted all aspects of the FTC DNCR. Now all >long-distance phone companies >airlines >banks and credit unions; and >the business of insurance, are fully covered and enforceable. count one for the good guys!! -----Original Message----- From: Roland Perry [mailto:roland@linx.net] Sent: Monday, June 30, 2003 12:03 PM To: nanog(a)nanog.org Subject: Re: National Do Not Call Registry has opened In message <A44DA7EDD8262343B02C64AF7E063A07A55349(a)kenya.ba.tronet.sk>, Tomas Daniska <tomas(a)tronet.com> writes ><quote> >Q: If I register my number on the National Do Not Call Registry, will it stop all telemarketing calls? > >A: No. Placing your number on the National Do Not Call Registry will stop most, but not all, telemarketing calls. Some businesses are exempt >from the national registry and still can call you even if you place your number on it. Exempt businesses include: > >long-distance phone companies >airlines >banks and credit unions; and >the business of insurance, to the extent that it is regulated by state law. All the above text has now disappeared from their site ! -- Roland Perry, LINX

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RE: Newbie network upgrade question, apologies in advance to NANOG
by Ejay Hire 03 Jul '03

03 Jul '03

This isn't the exact same situation, but in a similar vein...I'll offer this real-world experience. I once worked for a client that had 2 full t1's, and a 768k t1 in a multilink bundle. The fragmentation and reordering done by PPP was keeping the CPU load at %80+, and the jitter was terrible. Breaking the bundle and dedicating the 768k for videoconferencing and doing per-packet load sharing on the 2 x t1 for data fixed all the probelms they were having. (It also increased the data throughput for backups significantly.) -Ejay -----Original Message----- From: Vandy Hamidi [mailto:vandy.hamidi@markettools.com] Sent: Wed 7/2/2003 3:35 PM To: prue Cc: nanog(a)merit.edu Subject: RE: Newbie network upgrade question, apologies in advance to NANOG I would agree only under certain limited situations. Per packet load balancing COULD increase jitter, and if you're running VOIP (or similar protocols) could degrade performance. It could also affect TCP performance (on OSes not SACK enabled) as well. This would only really happen if you're T1's are near capacity (~above 80% or so). Near when queues start causing noticeable delays. If were talking about 2 identically configured T1's, on the same router, through the same loop provider, connected to one ISP--I highly doubt a situation where packet reordering would arise. It's not impossible, but unlikely as all the circuits would be utilized the same, thus queue delays should be similar across the board. I've done this on a private network with 4 T1's and never had a problem. We were pushing 100GB database dumps across it and performance did quadruple over the single T1. -=Vandy=- -----Original Message----- From: prue [mailto:prue@usc.edu] Sent: Wednesday, July 02, 2003 1:21 PM To: Vandy Hamidi Cc: nanog(a)merit.edu Subject: RE: Newbie network upgrade question, apologies in advance to NANOG Vandy, >Also, you may want to set your border router (the one with the serials to your >ISP) to route "per packet" as opposed to allowing the routes to cache. This >will distribute the bandwidtch evenly across your T1's. If you don't, then a >single high traffic session or destination can consume an uneven amount of >bandwidth on one of your lines. You can ask your ISP to do this as well for >incoming packets. That is not such a good idea generally. If you do this then you get packet reordering. This can be detrimental to TCP performance. Walt

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thoughts for the day concerning nocs and abusedesks
by Paul Vixie 03 Jul '03

03 Jul '03

listen up, you abusedeskers. if you aren't going to track spammers/abusers WITHIN A FEW HOURS, don't bother, they're LONG GONE by that time. if you want help from victims in keeping your network clean, READ THE COMPLAINTS. if you want information intact by the time it reaches you, ACCEPT ATTACHMENTS. and of course if you want to hear my replies to your mail, set your "reply-to" to some address other than "nobody@". (this rant happens to be the result of uunet robotics, but could be anybody's.)

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RATE-Limiting and
by Vandy Hamidi 03 Jul '03

03 Jul '03

Excellent point. It does depend on the traffic type. Though I don't like to complicated my configs, you can always use CAR (cisco rate limiting) through an ACL to protect against the file transfer from the core servers issue you referred to below. It can make sure a high bandwidth xfer won't suck up all your available B/W. Does anyone out there know how to limit B/W based on Flow or individual sessions? Or even just source (where source is random). For example, a CAR where each IP source gets no more than X% of B/W (still allowing bursts if bandwidth is available). I think some QOS tagging and queuing would have to be involved. -=Vandy=- -----Original Message----- From: Jack Bates [mailto:jbates@brightok.net] Sent: Thursday, July 03, 2003 4:43 AM To: Andy Dills Cc: Vandy Hamidi; prue; nanog(a)merit.edu Subject: Re: Newbie network upgrade question, apologies in advance to NANOG Andy Dills wrote: > > Yes, but the original poster was dealing with DS3s connected to different > NAPs, which is why the packet out-of-order issue can be significant. > I'd say that a more significant issue is customer throughput. The nice aspect of per conn is that it not only tends to keep a decent load balance, it also limits bandwidth hogs from saturating all circuits. This of course depends on your desired result. An example in my case is my helpdesk. They are off two t1's with dsl and dialup customers. I'd prefer them not to tank both t1's when transfering files to and from the core servers. -Jack

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RE: Newbie network upgrade question, apologies in advance to NANOG
by Vandy Hamidi 03 Jul '03

03 Jul '03

I would agree only under certain limited situations. Per packet load balancing COULD increase jitter, and if you're running VOIP (or similar protocols) could degrade performance. It could also affect TCP performance (on OSes not SACK enabled) as well. This would only really happen if you're T1's are near capacity (~above 80% or so). Near when queues start causing noticeable delays. If were talking about 2 identically configured T1's, on the same router, through the same loop provider, connected to one ISP--I highly doubt a situation where packet reordering would arise. It's not impossible, but unlikely as all the circuits would be utilized the same, thus queue delays should be similar across the board. I've done this on a private network with 4 T1's and never had a problem. We were pushing 100GB database dumps across it and performance did quadruple over the single T1. -=Vandy=- -----Original Message----- From: prue [mailto:prue@usc.edu] Sent: Wednesday, July 02, 2003 1:21 PM To: Vandy Hamidi Cc: nanog(a)merit.edu Subject: RE: Newbie network upgrade question, apologies in advance to NANOG Vandy, >Also, you may want to set your border router (the one with the serials to your >ISP) to route "per packet" as opposed to allowing the routes to cache. This >will distribute the bandwidtch evenly across your T1's. If you don't, then a >single high traffic session or destination can consume an uneven amount of >bandwidth on one of your lines. You can ask your ISP to do this as well for >incoming packets. That is not such a good idea generally. If you do this then you get packet reordering. This can be detrimental to TCP performance. Walt

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Re: National Do Not Call Registry has opened
by Steven M. Bellovin 02 Jul '03

02 Jul '03

In message <000401c340e0$aab42310$19ee0b0a(a)force10networks.com>, "Stephen Sprun k" writes: > >Thus spake "Tomas Daniska" <tomas(a)tronet.com> >> A: No. Placing your number on the National Do Not Call Registry will stop >most, but not all, telemarketing calls. Some businesses are exempt from the >national registry and still can call you even if you place your number on >it. Exempt businesses include: >> >> long-distance phone companies >> airlines >> banks and credit unions; and >> the business of insurance, to the extent that it is regulated by state >law. >> ... political organizations, charities, telephone surveyors or ... > >Nearly every call I get today is by companies on the 'exempt' list, go >figure. > Oh, it might get worse -- here's the first paragraph of a Wall Street Journal story: NEW YORK -- With millions of people signing up to stop receiving pesky sales calls, the nation's biggest marketers are preparing a new round of potentially annoying advertising pitches via e-mail and direct mail. Oh, joy -- more spam instead of telemarketers. --Steve Bellovin, http://www.research.att.com/~smb (me) http://www.wilyhacker.com (2nd edition of "Firewalls" book)

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Re: AS-Tree Utility
by Russ Haynal 02 Jul '03

02 Jul '03

These online tools provide visually interesting AS-related maps: Graphical AS Matrix: http://www.netlantis.org/index.html?menu=2&page=sagm Graphical AS Path: http://www.netlantis.org/index.php?menu=2&page=gasp Jasvpi (Java Autonomous System Path visualization): http://lab.verat.net/Jaspvi/ At 01:16 PM 6/27/2003 -0500, Malayter, Christopher wrote: I'm curious if anyone could point me to a utility for AS-Tree mapping from a routing table output? I searched the archive a bit, and didn't find anything. Thanks ahead! -Chris/AS4181 _________________________________________________________________ Russ Haynal - Internet Instructor, Speaker and Paradigm Shaker "Helping organizations gain the most benefit from the Internet" russ(a)navigators.com http://navigators.com 703-729-1757

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Sources for cheap/used lan testing equipment?
by Stephen Milton 02 Jul '03

02 Jul '03

Checked ebay, and there wasn't much available. Need something for 10/100 ethernet cable testing, as well as diagnostics. Like Fluke LanMeter 685 or such. TIA. Steve Milton ISOMEDIA.COM

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