C2950 causing intermittent network problems

[rmehta]

I have upgraded my network infrastructure from hubs to 2 c2950/24 port 10/100 autosensing switches. I have all of my desktops and Win/2000 servers connected to cisco switches. I have one hub with AS400 and remote sites inter-connected to the cisco switch. I have a Symantec200R/VPN box connected to the cisco. The problem is that when users boot up their PC, enter username and password, windows message pops up, "No domain controller available to authenticate....". You reboot couple of times eventually it will find the domain. Second problem is during the day users sessions on the AS400 will hang or dropped or PC will just hang and cold reboot required. I changed all of my PC's to static speed 10/full dup. That helped for 2 days and again after rebooting one PC not able to find the domain. My next action plan is to change all user ports to 100/half dup on the cisco and on all PC's.

Any suggestions? Please advice soon, I'll be making any changes this weekend for trial and test. Before my boss ask me to throw the cisco switches out and put the dumb hubs back in.

[Prashanth Krishnappa]

Have you enabled "spanning-tree portfast" on interfaces directly connected to end stations? If not enable it. Also type in "switchport mode access" under interfaces

http://www.cisco.com/warp/public/473/12.html#startup2k

[rmehta]

Yes, Portfast is enabled on cisco ports, except for the two linked ports.

[deilert]

are you using auto negotiate on the switch ports ?

[rmehta]

No, I'm now using static speed on both ends ( switch and PC ). I think the network is pretty stable now. I had one PC hung and one takes longer to logon.

[eheinold]

have you tried to set the ports on the switch to portfast?

see http://www.cisco.com/warp/public/473/12.html for more information

regards

eva

[rmehta]

yes. And port settings are static at 100/half dup both PC and cisco ports.