have a friend who has 21 floors of a building in DFW, multiple switches, etc and they started to have latency issues this weekend where half if not all packet are being dropped to folder shares, printers, etc. Suggestions on how they can troubleshoot that? call in a company to help identify it? -Dennis
That could be a lot of things. Without a network drawing and access to the devices to dig further it is difficult to say. On Thu, Mar 18, 2010 at 10:56 AM, Dennis Dayman <dennis-lists@thenose.net> wrote:
have a friend who has 21 floors of a building in DFW, multiple switches, etc and they started to have latency issues this weekend where half if not all packet are being dropped to folder shares, printers, etc. Suggestions on how they can troubleshoot that? call in a company to help identify it?
-Dennis
Simplest would be to do a trace route from different sources or loop back interfaces to the servers/computers in question and see where latency starts spiking. this will at the very least point you to what device or devices are possibly over utilized. On Thu, Mar 18, 2010 at 7:56 AM, Dennis Dayman <dennis-lists@thenose.net>wrote:
Check CPU levels on each switch, pull traffic logs of trunk ports, check syslogs for flapping ports or weird errors. I'd guess someone plugged something underneath their desk they shouldn't have. Jason On Thu, Mar 18, 2010 at 10:06 AM, Edgar Valdes <edgargvaldes@gmail.com>wrote:
-- Jason Biel
On 3/18/2010 09:56, Dennis Dayman wrote:
I'd start with a map of the network mark the routes (paths) that work. Then redraw the map without those paths and mark which stations talk to which other stations. If that exercise discloses which equipment is broken, fix or replace it and start over. If it does not, and no other you-can-do-it-yourself tests or analyses come to mind, call for expensive help. (If they are competent, they will use an orderly analysis--that one is my favorite--I call it sectionalization. I'm not bright enough to deal with 21 floors. I have to sectionalize it to a particular horizontal or vertical before I can figure where to start.) -- Democracy: Three wolves and a sheep voting on the dinner menu. (A republic, using parliamentary law, protects the minority.) Requiescas in pace o email Ex turpi causa non oritur actio Eppure si rinfresca ICBM Targeting Information: http://tinyurl.com/4sqczs http://tinyurl.com/7tp8ml
On 3/18/2010 10:07, Larry Sheldon wrote:
Have I been banned? -- Democracy: Three wolves and a sheep voting on the dinner menu. (A republic, using parliamentary law, protects the minority.) Requiescas in pace o email Ex turpi causa non oritur actio Eppure si rinfresca ICBM Targeting Information: http://tinyurl.com/4sqczs http://tinyurl.com/7tp8ml
On 3/18/2010 10:07, Larry Sheldon wrote:
It would be interesting to know where this message has been for an hour and a half. -- Democracy: Three wolves and a sheep voting on the dinner menu. (A republic, using parliamentary law, protects the minority.) Requiescas in pace o email Ex turpi causa non oritur actio Eppure si rinfresca ICBM Targeting Information: http://tinyurl.com/4sqczs http://tinyurl.com/7tp8ml
On 18/03/10 11:48 -0500, Larry Sheldon wrote:
Received: from localhost ([::1] helo=s0.nanog.org) by s0.nanog.org with esmtp (Exim 4.68 (FreeBSD)) (envelope-from <nanog-bounces@nanog.org>) id 1NsIqy-0007si-VK; Thu, 18 Mar 2010 16:45:49 +0000 Received: from eastrmpop110.cox.net ([68.230.240.52]) by s0.nanog.org with esmtp (Exim 4.68 (FreeBSD)) (envelope-from <larrysheldon@cox.net>) id 1NsIq7-00072X-DV for nanog@nanog.org; Thu, 18 Mar 2010 16:44:56 +0000 Received: from eastrmimpo01.cox.net ([68.1.16.119]) by eastrmmtao107.cox.net (InterMail vM.8.00.01.00 201-2244-105-20090324) with ESMTP id <20100318150713.FCRZ18765.eastrmmtao107.cox.net@eastrmimpo01.cox.net> for <nanog@nanog.org>; Thu, 18 Mar 2010 11:07:13 -0400 Received: from [192.168.1.202] ([68.229.170.168]) by eastrmimpo01.cox.net with bizsmtp id uf7E1d00F3eLnoL02f7F7u; Thu, 18 Mar 2010 11:07:15 -0400 -- Dan White
On 3/18/2010 12:06, Dan White wrote:
That _is_ interesting! I wonder if there is a way to get to those headers from Thunderbird. Not much else works and I didn't even think to try. My bad. -- Democracy: Three wolves and a sheep voting on the dinner menu. (A republic, using parliamentary law, protects the minority.) Requiescas in pace o email Ex turpi causa non oritur actio Eppure si rinfresca ICBM Targeting Information: http://tinyurl.com/4sqczs http://tinyurl.com/7tp8ml
On 3/18/2010 12:12, Larry Sheldon wrote:
On 3/18/2010 12:06, Dan White wrote:
[previous comments and header display]
It does work (takes a bit of poking to find them, but it does work). My very bad. -- Democracy: Three wolves and a sheep voting on the dinner menu. (A republic, using parliamentary law, protects the minority.) Requiescas in pace o email Ex turpi causa non oritur actio Eppure si rinfresca ICBM Targeting Information: http://tinyurl.com/4sqczs http://tinyurl.com/7tp8ml
I wonder if there is a way to get to those headers from Thunderbird. Not much else works and I didn't even think to try.
Ctrl + U (or "View" and then "Message source"). As an aside .. we see this all the time with some of the cable providers (we have both Cox and TWC here in Cleveland) when investigating wrongly-placed blame for "missing" or "delayed" emails. One server at TWC (which still has an *.adelphia.net name) in particular seemed to hold messages for the default retry interval 100% of the time (misconfigured greylisting?). Cheers, Michael Holstein Cleveland State University
on of the first things I'd do is check interface statistics from the inter-connecting interfaces for errors. On Cisco switches, the command is fairly straight forward - show interface counters errors. All of the numbers should be low if things are operating well...if you see more than 100 errors on any given port, it is probably worth investigating. Question - are the floors connected by fiber or by copper? On Thu, Mar 18, 2010 at 10:56 AM, Dennis Dayman <dennis-lists@thenose.net>wrote:
-- To him who is able to keep you from falling and to present you before his glorious presence without fault and with great joy
Hi, Am 18.03.10 15:56 schrieb Dennis Dayman:
call in a company to help identify it?
yes. Regards, Malte -- Malte von dem Hagen Teamleitung Network Engineering & Operation Abteilung Technik ----------------------------------------------------------------------- Host Europe GmbH - http://www.hosteurope.de Welserstraße 14 - 51149 Köln - Germany Telefon: 0800 467 8387 - Fax: +49 180 5 66 3233 (*) HRB 28495 Amtsgericht Köln - USt-IdNr.: DE187370678 Geschäftsführer: Uwe Braun - Alex Collins - Mark Joseph - Patrick Pulvermüller (*) 0,14 EUR/Min. aus dem dt. Festnetz; maximal 0,42 EUR/Min. aus den dt. Mobilfunknetzen
Found a MAC address spewing stuff. looks like we have our culprit. thanks EVERYONE! -Dennis On Mar 18, 2010, at 9:56 AM, Dennis Dayman wrote:
have a friend who has 21 floors of a building in DFW, multiple switches, etc and they started to have latency issues this weekend where half if not all packet are being dropped to folder shares, printers, etc. Suggestions on how they can troubleshoot that? call in a company to help identify it?
-Dennis
On 3/18/2010 11:00, Brandon Kim wrote:
Good question. Without thinking about it I saw in my mind's eye a situation we used to see at $EX-EMPLOYER (who was fond of the absolute smallest-dollar-amount-per-immediate-problem "solutions") who bout toy 4-port hubs by the pallet-load. These little gems had the endearing habit of spewing random bits onto the wire whenever the wall-wart failed--which they frequently did. I had MRTG graphs of every switch and router port so I could quickly determine which leg the current culprit was on. Never solved the problem of having two or three go bad, which, believe it or not, complicates the issue. But the graphs did allow me to identify the port and shut it down saving the rest of the network.
-- Democracy: Three wolves and a sheep voting on the dinner menu. (A republic, using parliamentary law, protects the minority.) Requiescas in pace o email Ex turpi causa non oritur actio Eppure si rinfresca ICBM Targeting Information: http://tinyurl.com/4sqczs http://tinyurl.com/7tp8ml
Great! looking forward to it...... Subject: Re: Latency quesstion From: dennis-lists@thenose.net Date: Thu, 18 Mar 2010 11:21:15 -0500 CC: nanog@nanog.org To: brandon.kim@brandontek.com yea, I'm working on that. will get back to you once he answers my IM I too would be interested for my own companies. -Dennis On Mar 18, 2010, at 11:00 AM, Brandon Kim wrote:That was pretty quick. But what do you mean by spewing stuff? It would help the rest of us understand for possible future issues we may run into ourselves.....
participants (11)
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Brandon Kim
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Charles Mills
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Dan White
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Dennis Dayman
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Edgar Valdes
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Jason Biel
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Larry Sheldon
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Malte von dem Hagen
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Michael Holstein
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Ravi Pina
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Steven Fischer