Switches

Performance checks

History of CPU load

sh processes cpu history

Current cpu load by process

sh processes cpu

Very often process ios-base taking more then 30% of CPU To see the details of process:

sh processes cpu detailed  16406

Verify often RACL could cause a huge load, to check do:

sh processes cpu detailed  16406 | i RACL

Checking VLANs

List of vlans and ports in access mode in these vlnas

sh vlan

List of vlans including trunk ports having these vlans

sh vlna all-ports

List of IP and MAC seen in particular VLAN

sh arp | i Vlan50

Configuration

Creating VLAN

vlan 245
name Test_vlam
state active
sh vlans

Creating IP interface for vlan

interface vlan145
ip address 10.0.145.1 255.255.255.0
no shutdown

Checking IP interfaces status

sh ip interface brief

Checking trunk status

sh int Po111 trunk

Cisco switch as time source

swco01(config)#feature ntp
swco01(config)#ntp server 132.246.168.148
swco01(config)#ntp server 209.87.233.53  
swco01(config)#ntp server 72.38.65.102 
swco01(config)#ntp master 5 

To check the status do:

sh ntp associations
sh ntp associations details
sh ntp status

Useful commands

sh etherchannel 2 summary 
sh interfaces Po2 trunk 
sh interfaces Po2 
sh port-security address