Packet Loss on switched network [7:64411]
Another problem Sys admins here have noticed that when trying to ping some of the switch's, some of the packets simply die in transit. Other people have said that the speed of file transfers here is getting poor. We have a simple network here, 3 levels, each having 4x 2950's, connect via Gigabit to the single core 4006 with SupIII. I have tested this and I notice bizzare ping reply times (500ms) when I try to ping from the core to one of the floor switch's. On the level I work on, we dont use fibre back to the core, as we are on the same level and use copper, and I dont see this problem, however I still connect to the Gigabit module on the Cat4006. I have checked all I can think of such as looking for loops on the network, checked my syslog messages, but I can find nothing that would suggest thats a fault in the configs of my switchs. Could any one point me as to where I could look for problems as I am now at a loss why we experience packet loss from the core to any switch connected via fibre to a 2950. It could be just due to the amount of traffic on the network, but I doubt it.. Thanks all John Sydney Australia ** visit http://www.solution6.com UK Customers - http://www.solution6.co.uk ** The Solution 6 Head Office and NSW Branch has moved premises. Please make sure you have updated your records with our new details. Level 14, 383 Kent Street, Sydney NSW 2000. General Phone: 61 2 9278 0666 General Fax: 61 2 9278 0555 ** This email message (and attachments) may contain information that is confidential to Solution 6. If you are not the intended recipient you cannot use, distribute or copy the message or attachments. In such a case, please notify the sender by return email immediately and erase all copies of the message and attachments. Opinions, conclusions and other information in this message and attachments that do not relate to the official business of Solution 6 are neither given nor endorsed by it. * Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=64411t=64411 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: Packet Loss on switched network [7:64411]
Quick answer: 1) Don't test with ping to the switches. Switches and routers de-prioritize pings. Their job is to forward frames as fast as possible and that's what they prioritize. 2) Test with applications that your users actually use and that require the switch to forward frames or 3) Test with pings going through the switch not to the switch. 4) Do show interface (or equivalent if that command isn't available on your swithces) and check the results for collisions, errors, etc. 5) Check for duplex mismatch problems, which will be evidenced by collisions, errors. 6) Do a trace-route end to end. Is this really just a Layer 2 switched network or (dare I say it) is there a Layer 3 switch in the picture? Send us some output from the show commands and we'll help you. ___ Priscilla Oppenheimer www.troubleshootingnetworks.com www.priscilla.com John Brandis wrote: Another problem Sys admins here have noticed that when trying to ping some of the switch's, some of the packets simply die in transit. Other people have said that the speed of file transfers here is getting poor. We have a simple network here, 3 levels, each having 4x 2950's, connect via Gigabit to the single core 4006 with SupIII. I have tested this and I notice bizzare ping reply times (500ms) when I try to ping from the core to one of the floor switch's. On the level I work on, we dont use fibre back to the core, as we are on the same level and use copper, and I dont see this problem, however I still connect to the Gigabit module on the Cat4006. I have checked all I can think of such as looking for loops on the network, checked my syslog messages, but I can find nothing that would suggest thats a fault in the configs of my switchs. Could any one point me as to where I could look for problems as I am now at a loss why we experience packet loss from the core to any switch connected via fibre to a 2950. It could be just due to the amount of traffic on the network, but I doubt it.. Thanks all John Sydney Australia ** visit http://www.solution6.com UK Customers - http://www.solution6.co.uk ** The Solution 6 Head Office and NSW Branch has moved premises. Please make sure you have updated your records with our new details. Level 14, 383 Kent Street, Sydney NSW 2000. General Phone: 61 2 9278 0666 General Fax: 61 2 9278 0555 ** This email message (and attachments) may contain information that is confidential to Solution 6. If you are not the intended recipient you cannot use, distribute or copy the message or attachments. In such a case, please notify the sender by return email immediately and erase all copies of the message and attachments. Opinions, conclusions and other information in this message and attachments that do not relate to the official business of Solution 6 are neither given nor endorsed by it. * Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=64414t=64411 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: Packet Loss on switched network [7:64411]
we had similar symptoms and without having much information from you, your problem may or may not be the same as mine--what we found was that even though we had forced the speed and the duplex on the switch, the server NIC's were still at auto detect. Once we changed the servers to 100/full the problems vanished. these were all intel servers running Win NT, Win2K and Linux. Needless to say it is now SOP for the sysadmins to set the speed and duplex on new servers :-) do show port on the 4006 and sh interface on the 2950's and look at the type of errors... John Brandis wrote in message news:[EMAIL PROTECTED] Another problem Sys admins here have noticed that when trying to ping some of the switch's, some of the packets simply die in transit. Other people have said that the speed of file transfers here is getting poor. We have a simple network here, 3 levels, each having 4x 2950's, connect via Gigabit to the single core 4006 with SupIII. I have tested this and I notice bizzare ping reply times (500ms) when I try to ping from the core to one of the floor switch's. On the level I work on, we dont use fibre back to the core, as we are on the same level and use copper, and I dont see this problem, however I still connect to the Gigabit module on the Cat4006. I have checked all I can think of such as looking for loops on the network, checked my syslog messages, but I can find nothing that would suggest thats a fault in the configs of my switchs. Could any one point me as to where I could look for problems as I am now at a loss why we experience packet loss from the core to any switch connected via fibre to a 2950. It could be just due to the amount of traffic on the network, but I doubt it.. Thanks all John Sydney Australia ** visit http://www.solution6.com UK Customers - http://www.solution6.co.uk ** The Solution 6 Head Office and NSW Branch has moved premises. Please make sure you have updated your records with our new details. Level 14, 383 Kent Street, Sydney NSW 2000. General Phone: 61 2 9278 0666 General Fax: 61 2 9278 0555 ** This email message (and attachments) may contain information that is confidential to Solution 6. If you are not the intended recipient you cannot use, distribute or copy the message or attachments. In such a case, please notify the sender by return email immediately and erase all copies of the message and attachments. Opinions, conclusions and other information in this message and attachments that do not relate to the official business of Solution 6 are neither given nor endorsed by it. * Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=64416t=64411 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
