In the switch configuration, there are ports which cannot be used when connecting to other switch.This connection is possible only through few ports.So when connecting two switches you should use a crossover cable only o ports where:
“spanning-tree portfast” is NOT configured.
Broadcast or Multicast policy is enabled
"Storm-control"configuration are enabled
The “show startup -config"command shows configuration of each port.Following is an examble of port config.
description crossover cable
no ip address
switchport mode access
storm-control action trap
srr-que bandwidth share 1 2 3 4
prority queue out
servive policy input cda_policy
storm-control broadcast level bps 20M 18M
storm-control Multicast level bps 20M 18M”