Cisco Routers

Cisco Routers Commands

Enable commands

• en

Show MAC address table

• show mac-address-table

Show VLAN Information

• show vlan brief

Show IP address assignments and status of interfaces

• show ip interface brief

Show DHCP info

• show ip dhcp pool

Show which IP addresses are associated with which MAC addresses

• show ip dhcp binding

Show DHCP errors / IP conflicts

• show ip dhcp conflict

Show NAT translation table

• show ip nat translations
• show ip nat statistics

Show ARP cache

• show arp

Clear arp cache

• clear arp-cache

Put into config mode

• conf t

Create VLAN

• vlan <number>
• name <name>
• exit

Configure VLAN

• interface range Gig <port range>
• switchport mode access
• switchport access vlan <number>
• end

Show interfaces command - shows trunks

• show interfaces trunk

Configure Trunk

• interface gig <port>
• switchport trunk encapsulation dot1q
• switchport mode trunk
• end

Write command - write config to memory to keep changes after reboot

• wr

shutdown port

• conf t
• int
• g <port number>
• shutdown

Enable port

• conf t
• int
• g <port number>
• no shutdown

Port mirroring

• monitor session <number of session> source int g <port>
• monitor session <number of session> destination int g <port>

Show IP Routes

• show iproute

Configure route

• conf t
• ip route <ipaddress of network> <subnet mask of network> <next hop - ipaddress of next router>

Copy running config to flash memory

• copy run flash

DNS Commands

To setup a Router as a DNS Client:

• ip domain-lookup
• ip name-server <dns server ip address>
• ip domain-name <FQDN of domain eg piszczynski.com>
• ip domain-list <FQDN of any other domains>

To setup as a server use these commands additionally:

• ipdns server
• ip host <hostname> <ip address of host>