Cisco Internetwork Operating System (IOS) is a family of network operating systems used on many Cisco Systems routers and current Cisco network switches

Basic commands edit


  • show interfaces
  • show interface trunk
  • show interfaces switchport. To display the administrative and operational status of a switching (nonrouting) port

  • show ip
  • show ip interface
    • show ip interface brief or sh ip int br
  • enable Logs into enable mode. Also known as user exec mode or privileged mode. See also: show privilege
    • enable 5 Change to level 5
    • no enable password

  • ip route-cache
  • no ip route-cache
  • include, similar to grep linux command

Access List edit

Configuring IP Access Lists:

Types of ACLs: Standard ACLs, Extended ACLs, Lock and Key (Dynamic ACLs), IP Named ACLs, Reflexive ACLs, Time-Based ACLs Using Time Ranges, Commented IP ACL Entries, Context-Based Access Control, Authentication Proxy, Turbo ACLs, Distributed Time-Based ACLs, Receive ACLs, Infrastructure Protection ACLs, Transit ACLs.

  • show access-list
  • show ip access-list
  • router(config)#access-list 101 deny icmp any any
  • router(config)#access-list 101 permit ip any any

  • router(config)#ip access-list extended test
  • router(config-ext-nacl)#permit ip host host
  • router(config-ext-nacl)#permit tcp host host eq www
  • router(config-ext-nacl)#permit icmp any any
  • router(config-ext-nacl)#permit udp host eq domain

  • ip access-group

HTTP Server edit

  • sh ip http server all
  • R1(config)#ip http authentication local
  • R1(config)#ip http secure-server

Configuration Guides edit

Activities edit

  1. Read wikipedia article about Cisco Internetwork Operating System
  2. Read Cisco IOS command reference:
  3. Read Cisco IOS Cheat Sheet:
  4. Configure a user with public key access Configure public RSA key authentication
  5. Associate a user with default higher privileges using username command

See also edit