!hostname switch
hostname switchN

interface VLAN1
! ip address 192.168.X.3 255.255.255.0
 ip address 192.168.X.50+N 255.255.255.0
 no shutdown

!ip default-gateway 192.168.X.1

!ip name-server 192.168.X.10

!ip domain-name corpX.un

ИЛИ

no ip domain lookup

ip host server 192.168.X.10

!ip host router 192.168.X.1

• Native VLAN

show vtp status

show vlan

dir flash:/vlan.dat

interface FastEthernet 0/1
 switchport mode trunk

interface FastEthernet 0/2
 switchport mode access
 switchport access vlan 2

interface Port-channel1
 desc uplink to CORE (switch1 and switch2)

interface FastEthernet0/0
 channel-group 1 mode on

interface FastEthernet0/1
 channel-group 1 mode on
! shutdown   ! in GNS

!!! may not be in some ealer ios !!!
dot1x system-auth-control

interface FastEthernet0/2

 switchport mode access

 spanning-tree portfast
 dot1x port-control auto

!!! modern syntax 
! authentication port-control auto
! dot1x pae authenticator

switch#show int f0/2

switch#show dot1x interface f0/2

mac-address-table static 001d.7d0c.062f vlan 1 drop

http://xgu.ru/wiki/DHCP_snooping

ip dhcp snooping
ip dhcp snooping vlan 1

interface FastEthernet 0/1
  ip dhcp snooping trust

• Tools to generate broadcast traffic
• В GNS эмуляторе коммутатора не поддерживаются счетчики на интерфейсе show interfaces f0/2

interface FastEthernet 0/2
 storm-control broadcast level 1
 storm-control multicast level 1
! storm-control action trap
! storm-control action shutdown

show storm-control

show interfaces | inc err-disable

monitor session 1 source interface f0/0 both

monitor session 1 destination interface f0/15

• Настройка Port Security на коммутаторах Cisco

switchport port-security
switchport port-security maximum 2
switchport port-security violation restrict
switchport port-security mac-address 0005.5E80.22A3
switchport port-security mac-address 00E0.F75B.C101