XLR-1100 issue

[Guest_imported]

i have a connectivity issue with an OS-2 server using RPL protocol to communicate with clients .. clients are distributed across floors with dirsct connection to 450 switch- stacks , all floors are connected to a backbone XLR-1100 switch with fiber connections , now if a client tries to connect to a server it will face slow response and sometime fails to connect to the server unless the client and server were on the same stack then , eveything works fine , i tried to bypass the xlr by connectig two 450 stacks directely (through fiber ) it worked fine , also i noticed that if the xlr-1100 is connected to the 450 stacks with UTP connection it will work fine too !!

Note : STP is disabled on all ports on the switches and on the xlr port level and global . any idea that can help !!

 

[ZachBenj]

Do you have more than one type of VLAN on the Fiber port?
How many fiber are you using between XLR and a 450 switch?

 

[Guest_imported]

Fiber does not auto negotiate like Copper be sure all your fiber ports are manually set to full duplex. A mix of full and half duplex will be slow and unreliable

 

[Guest_imported]

exactely !! that what i did i forced all connections to be on full duplex and everything worked fine !! thanx for the hint !