From: Main, Kerry [Kerry.Main@Compaq.com] Sent: Wednesday, July 21, 1999 9:03 PM To: Info-VAX@Mvb.Saic.Com Subject: RE: Network is extremely slow on 3COM switches As Dave mentioned in the attached - Ensure auto-negotiation is OFF at both ends. Physically, via the console, set the Alpha system ethernet speeds to full duplex, 100Mb (assuming 10/100 DE500) by the following command: >>> SET EWA0_MODE FASTFD >>> Also, make sure the 3Com / Bay stuff is also set to 100Mb Full duplex. ** Incorrect settings between system and net gear will result in a working network, but the performance will be extremely slow. Regards, Kerry Main Senior Consultant, Compaq Canada Inc. Voice : 613-591-5078 / 621-5078 (dtn) Fax : 613-591-5113 Email : kerry.main@compaq.com -----Original Message----- From: Dave Pickles [mailto:davep@nugate.demon.co.uk] Sent: Wednesday, July 21, 1999 1:50 PM To: Info-VAX@Mvb.Saic.Com Subject: Re: Network is extremely slow on 3COM switches "BBak" wrote: >We have a cluster with a VAXStation 4000-90 version 7.2, an AlphaStation >200/166 version 7.0, and an Alpha Server 2100 version 7.2. We began to see >degraded performance a few weeks ago (after changing from a Bay Network >switch to 3Com switches. We enabled Decnet for the cluster on these >machines and for packet rates VERY low...3 - 10 KB/s when we could even get >them to connect. When they are on a local hub they have packet transfers >between 280 and 350 KB/s for local traffic. Anything outside the switch >that needs to be accessed is still VERY slow. We tried a different (same >model) switch and same poor performance. Switch=3Com Superstack 3300. Has >anyone dealt with a similar problem? Sidenote = We Upgraded to Gig-E >Backbone with 100baseT switches...we have tried setting the switch ports to >Auto-negotiate 10/100 off and manually set them to 10Mb/s Half duplex with >poor results. I've certainly seen strange behaviour on the 3300 hubs. One particular revision of one particular 3Com PCI network card gave just the behaviour you see, though obviously that's not relevant to your problem. Have you tried setting auto-negotiation OFF for both the hub and (where appropriate) the node? What do the error counts on the port say? What firmware revision is on your 3300? -- Dave Pickles