This directory contains a set of pages describing various problems, relevant information, how they were tackled and possibly resolved. The date is roughly when the page for this problem was created.
Date | Link | Summary | Status |
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December 30, 2011 | wget in getdata.pl fails to pinger.pern.edu.pk with a URL that works if from a browser |
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December 29, 2011 | Can't ping pingerisl-fjwu.pern.edu.pk or pinger.pern.edu.pk from anywhere but Pakistan and Jordan | Probably a remote host or remote network/firewall configuration | |
August 17, 2010 |
| Appears it is a host related problem at DESY - UNDERSTOOD | |
August 23, 2007 | Getting two different IP addresses when trying to resolve host name. | NIIT DNS servers were out of sync and both were down - UNDERSTOOD | |
July 8, 2007 | Routing loop blocked access, unable to report problem. | Loss of power at COMSats - UNDERSTOOD | |
July 1, 2007 | Long delays loading SLAC home page on Visitor network using wireless | SKYPE (or other P2P application) was using the host as a supernode - UNDERSTOOD | |
June 26, 2007 | Offiste connections to some sites was very poor | STILL DIAGNOSING | |
December 1, 2006 | User wants to increase throughput between SLAC and UVic | Partially UNDERSTOOD | |
August 22, 2006: | BNL unreachable from some places - |
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NOT RESOLVED | |
August 4, 2006 |
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Denial of Service attack, followed by loss of power |
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UNDERSTOOD. | |
July 25, 2006 |
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Power problems in Akademogorock region causes many services to be unavailable from SLAC to BINP | -UNDERSTOOD. | |
May 18, 2006 |
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Too small TCP windows set at default, firewall limiting throughput, application needs to apply ssh throughput patches, mandated application cannot use multiple streams or big windows, alternate path had port blocking. | -UNDERSTOOD. | |
May 14, 2006 |
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TCP windows and number of parallel styreams needed optimizing | UNDERSTOOD. |
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May 9, 2006 |
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Change in routing traffic from S. Africa to CERN from using GEANT to going via Abilene and the U.S. after Abilene started exchanging traffic with S. African TENET |
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UNDERSTOOD |
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. |
February 1, 2006 |
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Appears to be an application problem |
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UNDERSTOOD. | |
January 22, 2006 |
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San Diego Sunnyvale connectivity was interrupted by Level(3) maintenance. An alternate path was used. This study looks at the impact on the various IEPM metrics of the route change |
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UNDERSTOOD | |
December 28, 2005 |
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Multiple paths seen from and to BNL showed step downs in pathchirp performanceBelieved to be related to the host at BNL |
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NOT |
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RESOLVED |
September 10, 2005 |
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Fan failure in Cisco 15454 causes route to CENIC/Sunnyvale to fail, and switch over to using ESnet |
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UNDERSTOOD |
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August 16, 2005 |
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Fiber cut causes OC48 outage and fail over to a T3 |
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link | UNDERSTOOD |
July 1, 2004 |
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Fiber cut off coast of Karachi causes 12 day outage to |
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Pakistan | UNDERSTOOD |
May 31, 2005 |
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See the effect of the new route in improving RTT and |
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throughput | UNDERSTOOD. |
April 18, 2005 |
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Some change caused the connectivity between SLAC and BINP to be blocked by firewalls in Novosibirsk. | |
September 2, 2004 |
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Due to CENIC maintenance SLAC lost conectivity to many sites from around midnight until 10:30am |
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, |
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This is nicely illustrated in traceroutes taken each 10 minute interval to multiple sites from SLAC |
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and in particular can be nicely visualized by means of a topology map. | -UNDERSTOOD |
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February 25, 2004 |
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Shows Internet performance from SLAC to a few Pakistani sites, including: differences in performance depending on providers; identifying bottlenecks; effects of upgrade for NIIT; routing between Pakistani sites going via London |
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-UNDERSTOOD |
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January 8, 2004 |
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Site with better Internet connectivity had much larger RTTs, but lower losses - | UNDERSTOOD |
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October 3, 2003 |
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CENIC's routing to Caltech was incorrect |
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RESOLVED |
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July 23, 2003 |
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Abilene routing, traceroute analysis |
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RESOLVED |
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June 12, 2003 |
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2 problems, routing for IN2P3, incorrect iperf configuration for CESnet |
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RESOLVED. | |
June 10, 2003 |
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One of our important partner Daresbury lab (UK) upgraded line to Internet to |
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1GBitper second Routing | RESOLVED. |
June 6, 2003 |
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Routing | RESOLVED | |
May 22, 2003 |
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Routing | RESOLVED | |
May 20, 2003 |
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Misconfigured router |
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RESOLVED |
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May 7, 2003 |
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The influence of strong LAN traffic on target hosts in monitoring results (NERSC,ANL) | Effect of local NFS traffic |
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RESOLVED |
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November 6, 2002 |
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Change of routing |
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RESOLVED | |
September 20, 2002 |
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reports from BWESLAC-UK, and SLAC-ANL |
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RESOLVED | |
July 26, 2002 |
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following upgradeResults of effectiveness of network upgrade |
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RESOLVED |
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May 30, 2002 |
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Routing Change |
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RESOLVED | |
Mar 21, 2002 |
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Poor packet loss |
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RESOLVED | |
Jan 4, 2002 |
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Throughput from monitoring host suddenly dropped from several hundreds of Mbits |
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per second to about 100Mbits |
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per second due to turning on debugging flags |
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RESOLVED | |
Jan 8, 2002 |
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Only ~ 20Mbits/s throughput achievable on 30Mbps ATM VP bottleneck |
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RESOLVED | |
Dec 13, 2001 |
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Large router buffers adversely affect interactive use |
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RESOLVED | |
Sep 27, 2001 |
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Poor performance from SLAC to Rutherford Lab, UK caused by firewall and small windows |
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RESOLVED | |
Sep 19, 2001 |
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High packet loss prevents ssh access, due to host problems |
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RESOLVED | |
Sep 11, 2001 |
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How did the WTC collapse affect Internet connectivity for SLAC |
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RESOLVED. | |
May 3, 2001 |
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Need to find hosts/sites to try with QBone Scavenger services |
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RESOLVED | |
Mar 28, 2001 |
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Request for information on quality of International links |
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RESOLVED | |
Mar 19, 2001 |
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Request to understand the proposed effect of changing an ISP |
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RESOLVED | |
Mar 1, 2001 |
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Feb 25, 2001 |
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Feb 01Problems with users DSL service due to bad pairs to home |
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RESOLVED | |
Jan 27, 2001 |
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Problems in host to host throughput on LAN due to windows being to small |
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RESOLVED | |
Jan 22, 2001 |
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Problems with throughput between SLAc and IN2P3 due to misconfigured ATM/PVC |
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RESOLVED | |
Jan 12, 2001 |
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Problems between SLAC and a commercial site due to poor routing |
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RESOLVED | |
Dec 18, 2000 |
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Multiple probelms with throughput between SLAC and UTDallas due to small windows and packet loss |
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RESOLVED WINDOW |
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PROBLEM |
Dec 07, 2000 |
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User question on suitability of network connections to BaBar tier A regional computing site |
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RESOLVED | |
Dec 06, 2000 |
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Investigation of poor throughput from SLAC to Novosirbirsk, resulting in successful recommendation for link upgrade |
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RESOLVED | |
Sep 11, 2000 |
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partially |
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RESOLVED by moving from ESnet to Internet 2 |
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PARTIALLY |
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RESOLVED |
Sep 03, 2000 |
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Poor performance between SLAC and Israel caused by ESnet upgrade to router using incorrect BGP configuration |
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RESOLVED | |
May 16, 2000 |
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Poor throughput between SLAc and Stanford campus, required resetting an ATM interface |
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RESOLVED | |
May 09, 2000 |
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did not appear to be working, the direction it was applied in was not congested |
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RESOLVED | |
May 02, 2000 |
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Big asymmetry in the throughputs from SLAC to IN2P2 and vice versa, partially due to Cisco web cache |
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NOT |
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RESOLVED |
Apr 15, 2000 |
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Mainly some hints on tracking Microsoft VPN problems. | |
May 23, 1999 |
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Pings from Linux to WNT on a LAN with normal RTT < 10 msec, manifest an unusual regularity in the sequence number separation of the pings with > 10msec. Probably an OS effect. |
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RESOLVED |