What is the Software on Cisco Devices
Cisco IOS (Internetwork Operating System)
- Uses a Command Line Interface
- Commandas available are determined by mode
Common Cisco Commands
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- Displays Commands available in the current mode
- displays the next required component for a command
Show Running-Configuration
- shows current config in effect
- running config does not persist after reboot
- (switch)# copy run start
- used to save running config to startup config
Show ip interface brief
- displays status of all interfaces
**Show int <g/f>1/0/<x>**
- displays detailed information of a specific interface</x>
shutdown / no shutdown
**ping <ip>**
• Test ICMP connectivity to destination</ip>
show ip route
• Display routing table
Write erase
• Erases configuration of switch
show version
• Display version of IOS
**traceroute <ip>**
• Test/Display dev</ip>
Cisco IOS Modes
User Exec
Privileged Exec
Global Config
Interface Config
Sub-Interface Config
Setup
ROMMON
User EXEC mode
- Initial Level
- Temporary changes to terminal settings
- Basic tests
- List system info
1. Hostname>
Privileged EXEC mode
- sets operating parameters
- high level testing
- common commands
- show, copy, ping
- aka enable mode
- Hostname> enable
- Password: <password></password>
- Hostname#
- Hostname# end
- Hostname>
Global Config mode
- used for applying changes to entire device
- unable to perform some commands at the Priv EXEC mode without “do” “End” “Exit” or [Ctrl]+[C]
- Hostname> enable
- Hostname# configure terminal
- Hostname (config) #
- Hostname (config) #end
- Hostname>
Interface Config Mode
1.Hostname> enable
2.Hostname# configure terminal
3.Hostname(config)#
4.Hostname(config)#interface (g/f) 1/0/<X></X>
5.Hostname(config-if)#
6.Hostname(config-if)#end
7.Hostname>
Setup Mode
Used to initially configure a device
- Prompt at boot when no config exists
ROMMON Mode
Bootstrap program that initializes hardware of switch and boots IOS when no IOS is found
Router Configurations
Physical Connection
- Uses Console cable (DB-9) or on a newer device USB Mini
- If using console cable, may need serial to USB adapter
Tera Terminal
- Application for consoling into router or switch
Switch Confiuration
- Passwords
- Privileged EXEC
- One or the other, not both
- Unencrypted password
- switch (config) #enable password <password></password>
- VTY - config Telnet sessions
- switch (config) #line vty 0 <#>
- switch (config-line) #password <password></password>
- switch (config-line) #login
- switch#username <X> priv <X> password <X></X></X></X>
Hostname
- Switch (confi) #hostname <device> <Device>(config) #</Device></device>
Banner
- displayed when logging in via Telnet , any deliminating charecter
- Hostname (config) #banner %message%
IP Routing
- Enables routing between known networks in the switch (required for EIGRP statements)
EIGRP
- Dynamic Routing
- Works on router or switch
- Uses unique ASNs (Advertise Networks)
Hostname (config) #switch EIGRP <asn>
Hostname (config-switch) #network <net> <snm></snm></net></asn>
Configure Interface
- Hostname (config) #int gi<#/#>
Description
- Hostname (config-if) #desc <description></description>
Set IP
- Hostname (config-if) #no switchport
Open/Close
- Hostname (config-if) #no shut
- Hostname (config-if) #shut
Rules
- passwords
- Hostname
- banner
- configure ports (IP, desc, no shut)
- apply protocols (IP, routing, EIGRP)
- Configure inside -> out
- get inside net squared away first before trying to connect out
Routing
- Static
- used to define exit point of small networks
- Hostname (config) #ip route <destination> <dest> <gateway>
- Default Route
- Hostname (config) #ip route
192.168.121.0
255.255.255.0
192.168.120.1</gateway></dest></destination>
Config VLANs
- Hostname (conf) #vlan <#>
- Hostname (conf-vlan) #name <VLAN>
- Hostname (conf-vlan) #int vlan <X>
- Hostname (config-if) #</X></VLAN>
Assign interface to VLAN
•hostname(conf)#int gi0/0
•hostname(conf-if)#switchport mode access
•hostname(conf-if)#switchport access vlan<X>
•hostname(conf)#sho vlanbrief</X>
Network Security
Information Assurance
- Availability = ensure info is accessible by those authorized
- Integrity = Ensure it has been modified
- Authentication = make sure its legit
- Confidentiality = prevent unauthorized disclosure
- Non-repudiation = confirmation of receipt
ACLS
- standards (only filters by IP address)
- permit or deny
- Implicit Deny
- Create Rule
-router(config)#access-list <#> <permit|deny> <ip> <wild card|snm>
- router (config) #access-list <#> remark <description></description></ip>
Assign rule to interface
- router (config-if) #ip access-group <ACL#> <in|out>
