New Install of 8600 to six 450T stacks very slow Any Tips?

[JMDatDLR]

I recently replaced all of our 10 Mbit hubs and some switches with a 10 slot 8600 with 8 port gigabit fiber card.
The gig ports (six of them) go to new 450 stacks throughout the building that have the Gig MDA's in them.
Connectivity tested fine on the night of the install but when everyone came back to work on Monday things went from bad to worse. VERY Very Slow and Lost connections. We have since hard coded Speed and duplex for many of the ports. We thought STP might be the problem, disabled it and things got worse.We turned STP back on and updated the SW and boot code on the 8600 and the 450's We have a Single VLAN with about 300 clients. The largest stack of 450's we have is four. While the SW upgrade definetly helped. We still are experiencing significant slowdowns. Any ideas tips or solutions would be greatly appreciated!
Thanks
Jason

 

[bobthecat]

Hi Jason, about a year ago we had big problems with stack of 6*450t's using the correct cascade cables. We could not get to bottom of it and we had a lot of pressure to get it up and running. In the end we discarded the cascade cable and used an Ethernet port on each switch to connect them together. From that point on everything work fine, I dont know why but configured as a stack (with cascade cables) did not work for us. Before we installed them we did a pre-build and hammerd it with all the packets we could generate, no prblems. As soon as we went live it ran like a dog.

Best of luck

Bob ^^

 

[vila75]

what sw you have in the switches baystacks and 8600 ..! ..
do you have slowdown in all stacks !!? .. more details pls

 

[jimbopalmer]

I run a stack of 7 and a stack of 5 450s hooked to Accelar 1200s, no trouble, although I tend to make each stack it's own VLAN (also 3 stacks of 4, 3 stacks of 3, etc) The one thing you can't give for your heart's desire is your heart. - Lois McMaster Bujold

 

[mikefrank]

High Jason,

we also have 8600 with GigaBit Fibre and many Bay 450 with Giga MDA. We had the problem to connect the 450´s via the GigaBit MDA with the 8600. The way out was to disable the Autonegotiation on both sides!
The same problem is the Autonegotiation on the TP Ports. We have a very slow performance when we run e.g. 3COM Cards with Bay Switches. We must set the Speed hard on both sides (Netcard and Switch!) to 10MBit or 100MBit FDX (depends on your Netcard) then it Works!
You can test this with a ping command with a datasize of 64000 bits (Ping -l 64000 -t NodeName). There should be no packets dropped, the reply time must be about 10ms for 100FDx and 100ms for 10FDx connection.