CLI

%SYS-6-STARTUP_CONFIG_IGNORED: System startup configuration is ignored based on the configuration register setting.

sh version
...
Configuration register is 0x141

https://www.cisco.com/c/en/us/support/docs/routers/10000-series-routers/50421-config-register-use.html

enable
dir
conf term
boot system flash cat4500-ipbasek9-mz.122-54.SG1.bin
exit
config-register 0x102
copy run star
reload

It is possible to switch console baud rate after boot. It will be applied after system will bootup and executes startup-config.

configure terminal
line con 0
speed 9600
! note: now you need to reconfigure your terminal client to different baud rate
end
wr
copy run star

enable
config terminal
lldp run
exit
copy run start

show lldp neighbors

• show power inline

enable
configure terminal
snmp-server community public ro
snmp-server contact <itadmin@grinn-global.com>
snmp-server location GRINN - Serwerownia
exit
copy run start

enable
show vlan
configure terminal

! delete vlan 7
no vlan 7

! add tagged vlan 28
vlan 28
name admin
end

show vlan

configure terminal
interface range Gi0/1-28
switchport trunk encapsulation dot1q
switchport trunk native vlan 1
switchport trunk allowed vlan add 28,255
no shut
end

configure terminal
interface range Gi0/1-28
! to remove all ports from VLAN:
no switchport access vlan
end

enable
configure terminal
interface vlan 1
no ip address DHCP
no ip address
exit

int vlan 28
ip address 192.168.28.31 255.255.252.0
no shutdown
exit

ip default-gateway 192.168.28.1
ip name-server 192.168.28.1
exit

show ip redirects
show spanning-tree vlan 28
sh int vlan 28

copy running-config startup-config

wr
copy running-config startup-config

conf term
interface Gi1/48
switchport access vlan 28
end
wr

reload

show spanning-tree summary
enable
config
spanning-tree mode ?
spanning-tree mode rapid-pvst

spanning-tree vlan 1 priority 57344
spanning-tree vlan 2 priority 57344
spanning-tree vlan 28 priority 57344
spanning-tree vlan 255 priority 57344
exit

show spanning-tree bridge

wr
copy run star

Disable STP:

enable
config terminal
Switch(config)#no spanning-tree vlan 1
wr
copy run star

sh mac address-table vlan 1

show interface Gi0/40
show controllers

show interface counters
 
enable
clear counters

show interface Gi0/17

Using Time Domain Reflectometer

enable
test cable-diagnostics tdr int Gi0/17
show cable-diagnostics tdr int Gi0/17