dear

i changed date & time but when i restart my switch it's showing me default date & time

That is normal and the only way around that is to setup ntp on your switches . They are not battery backed up so they wills always go back to the default time when power cycled.

I agree with Glen on this.If no other source of time is available, you can manually configure the time and date after the system is restarted. The time remains accurate until the next system restart.

You can configure the switch as NTP client and configure one of your router as NTP server. Till the time you have the router up, no matter how many times the switch reboots, it will always sync the time with the NTP server.

HTH,

-amit singh

Dear

can you tell me how can i setup ntp server.

http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/ffun_c/fcfprt3/fcf012.htm#wp1001170