CCNA Commands
show cdp neighbors
A network engineer is interested in obtaining specific information relevant to the operation of both distribution and access layer Cisco devices. Which command provides common information relevant to both types of devices?
username [xxx] password [xxx]
Adding a user and password to the local database for SSH
CTRL-SHIFT-6
All purpose break sequence. used to abort DNS lookups, traceroutes and pings.
login block 180 attempt 3 within 60
Block logins for 3 mins if user login fails 3 times in 1 minute
nslookup
Command-line program in Windows used to determine exactly what information the DNS server is providing about a specific host name.
int G0/0 ip address XXX.XXX.XXX.XXX 255.255.255.0 desc XXXXX no shutdown
Configure interface on router
crypto key generate rsa [modulus 1024]
Create an RSA key for use with SSH
show arp
Display the layer 2 to layer 3 mapping on a router or switch
ipv6 unicast routing
Enable IPv6 routing
int vlan 1 ip add [x.x.x.x 255.255.255.0] no shut
Enable SVI on switch
(config)# sdm prefer dual [default] copy running-config startup-config reload
Enable ipV6 on switch
CTRL-K
Erases all characters from the cursor to the end of the command line
CTRL-D
Erases the character at the cursor
delete vlan.dat
How do you delete the VLAN.dat file?
Erase start
How do you erase the startup config?
Open TFTP software on PC host copy running-config tftp
Save the config to a tftp server
line vty 0 15 password XXX login
Secure remote Telnet / SSH access
transport input SSH TELNET
Set VTY lines to accept Telnet and SSH connections online
ipv6 add FE80::101 link-local
Set the ipv6 link local address
line vty 0 15 login local
Setting the VTY to login local
CTRL-C
Soft break, back to config mode
logging synchronous
Stops console messages from overwriting your command line input
! - ping completed successfully . - Did not receive message back from ICMP U - Responds with an ICMP unreachable message... couldn't find a route to destination
What are the three common responses from PING?
CTRL-Z
When in any configuration mode, ends the configuration mode and returns to privileged EXEC mode
terminal monitor
Which command should be used on a Cisco router or switch to allow log messages to be displayed on remotely connected sessions using Telnet or SSH?
erase start reload
clear router
erase start delete vlan 1 reload
clear switch
ip default-gateway XXX.XXX.XXX.XXX
configure the default gateway on a switch
no ip domain-lookup
disable DNS lookup
no ip domain-lookup
disable DNS lookup... won't try to covert bad command into an IP
show interfaces
display statistics for all interfaces on the device
show ip interface
display the IPv4 statistics for all interfaces on a router
service password-encryption
encrypt all plain text passwords
(config) line con 0 (config-line) password XXXX (config-line) login
how do you enable password on initial boot up?
Enable secret
how do you secure privileged exec mode?
security password min 8
set a minimum length of 8 characters for passwords
ip domain-name [domain name]
set the domain to XXX.com
banner motd
set the message of the day
show version
show info on version of Cisco IOS
show ip route
show the IPv4 routing table in RAM
do show run (if in config mode) -or- show running-config
show the running configuration