Introduction to the Cisco IOS

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Introduction to the Cisco IOS

• Presented by Dave Dindia
• ddindia_at_gmail.com
• January 26, 2009

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Introduction

• Who currently uses Cisco equipment?
• Purpose of presentation
• Introduction to the Cisco IOS
• Core networking/management commands
• Useful takeaways
• What well be setting up

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Topology
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Cisco 871 Rear View
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Requirements

• Cisco Router (Were using a Cisco 871)
• Switch (the 871 has a switch built-in)
• Windows XP Client
• Windows 2003 Server
• DNS
• Kiwi Syslog Daemon

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Access and Configuration Modes

• Cisco has lots of different modes.
• User Mode
• Cisco871gt
• Privileged Mode (enable mode)
• Cisco871gtenable
• Cisco871
• Global Configuration Mode
• Cisco871configure terminal
• Cisco871(config)

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Step 1 Basic IOS Administration

• Hostname
• Cisco871(config)hostname Cisco871
• Password protection
• Cisco871(config)enable secret Cisco871PW
• User account
• Cisco871(config)username CiscoAdmin secret
  CiscoAdmin99

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Step 1 Basic IOS Administration

• Disable Telnet
• Cisco871(config)line vty 0 4
• Cisco871(config-line)transport input ssh
• Enable SSH
• Cisco871(config)aaa new-model
• Cisco871(config)ip domain-name DomainName.com
• Cisco871(config)crypto key generate rsa
• Cisco871(config)ip ssh version 2
• Cisco871(config)ip ssh time-out 30
• Cisco871(config)ip ssh authentication-retries 5

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Step 1 Basic IOS Administration

• Save the configuration!
• Cisco871copy running-config startup-config
• Lots of ways to save the configuration
• Cisco871copy running-config ?
• FTP
• SCP
• TFTP

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Its Show Time

• Show commands display lots of useful info.
• Cisco871show running-config
• Current operating configuration
• Cisco871show ssh
• Status of SSH server connections
• Cisco871show ip ssh
• Information on SSH
• Cisco871show ip interface brief
• Brief IP interface status and configuration

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Step 2 IP Addressing, DNS and DHCP

• IP Addressing
• Cisco871(config)interface fastEthernet0
• Cisco871(config-if)description LAN Switch Ports
  INTERNAL
• Cisco871(config-if)switchport mode access
• Cisco871(config-if)no shutdown
• Cisco871(config)interface fastEthernet1
• Cisco871(config-if)description LAN Switch Ports
  INTERNAL
• Cisco871(config-if)switchport mode access
• Cisco871(config-if)no shutdown
• Cisco871(config)interface Vlan 1
• Cisco871(config-if)ip address 192.168.1.1
  255.255.255.0
• Cisco871(config-if)no shutdown

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Step 2 IP Addressing, DNS and DHCP

• DHCP and DNS
• Cisco871(config)ip dhcp pool InternalDHCP
• Cisco871(dhcp-config)network 192.168.1.0
  255.255.255.0
• Cisco871(dhcp-config)default-router 192.168.1.1
• Cisco871(dhcp-config)dns-server 192.168.1.10
• Cisco871(dhcp-config)domain-name MyDomain.com
• Cisco871(dhcp-config)lease 7
• Cisco871(config)ip dhcp excluded-address
  192.168.1.1 192.168.1.100

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Its Show Time!

• Show commands display lots of useful info.
• Cisco871show ip interface ?
• Displays IP interface status and configuration
• Cisco871show ip interface fastEthernet 0
• Cisco871show ip interface brief
• Cisco871show ip dhcp ?
• Displays binding, pool and DHCP server info.
• Cisco871show ip dhcp pool InternalDHCP
• Cisco871show ip dhcp server statistics

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Step 3 System Monitoring

• Configure NTP (optional)
• Cisco871(config)ntp server 192.168.1.11
• System events can be sent to a syslog server
• Cisco871(config)logging on
• Cisco871(config)logging 192.168.1.10
• You can specify the type of events logged
• Cisco871(config)logging trap 7

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Its Show Time!

• Show commands display lots of useful info.
• Cisco871show logging
• Show the contents of logging buffers
• Cisco871show logging history
• Show the contents of syslog history table

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Network Testing

• Windows XP Client (HostA)
• ipconfig /all
• ping ServerA
• SSH to the router
• Windows 2003 Server (ServerA)
• ipconfig /all
• ping HostA
• Kiwi Syslog

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Questions, Comments, etc?