I have had many people ask me about commands on switches and I was going to make a cheat sheet but Erik Rodriguez did such a nice job I am going to share his work Great job Erik

Cisco IOS Cheat Sheet

By Erik Rodriguez

These commands are used on all Cisco devices running the Cisco IOS. If you are unfamiliar with Cisco devices please see: Routers, Using the Cisco IOS.

ROUTER COMMANDS
TERMINAL CONTROLS:

• Config# terminal editing – allows for enhanced editing commands
• Config# terminal monitor – shows output on telnet session
• Config# terminal ipnetmask-format hexadecimal|bit-count|decimal – changes the format of subnet masksHOST NAME:
• Config# hostname ROUTER_NAMEBANNER:
• Config# banner motd # TYPE MESSAGE HERE # – # can be substituted for any character, must start and finish the messageDESCRIPTIONS:
• Config# description THIS IS THE SOUTH ROUTER – can be entered at the Config-if levelCLOCK:
• Config# clock timezone Central -6
  # clock set hh:mm:ss dd month yyyy – Example: clock set 14:35:00 25 August 2003CHANGING THE REGISTER:
• Config# config-register 0x2100 – ROM Monitor Mode
• Config# config-register 0x2101 – ROM boot
• Config# config-register 0x2102 – Boot from NVRAMBOOT SYSTEM:
• Config# boot system tftp FILENAME SERVER_IP – Example: boot system tftp 2600_ios.bin 192.168.14.2
• Config# boot system ROM
• Config# boot system flash – Then – Config# reloadCDP:
• Config# cdp run – Turns CDP on
• Config# cdpholdtime 180 – Sets the time that a device remains. Default is 180
• Config# cdp timer 30 – Sets the update timer.The default is 60
• Config# int Ethernet 0
• Config-if# cdp enable – Enables cdp on the interface
• Config-if# no cdp enable – Disables CDP on the interface
• Config# no cdp run – Turns CDP offHOST TABLE:
• Config# ip host ROUTER_NAME INT_Address – Example: ip host lab-a 192.168.5.1
  -or-
• Config# ip host RTR_NAME INT_ADD1 INT_ADD2 INT_ADD3 – Example: ip host lab-a 192.168.5.1 205.23.4.2 199.2.3.2 – (for e0, s0, s1)DOMAIN NAME SERVICES:
• Config# ip domain-lookup – Tell router to lookup domain names
• Config# ip name-server 122.22.2.2 – Location of DNS server
• Config# ip domain-name cisco.com – Domain to append to end of namesCLEARING COUNTERS:
• # clear interface Ethernet 0 – Clears counters on the specified interface
• # clear counters – Clears all interface counters
• # clear cdp counters – Clears CDP counters
  STATIC ROUTES:
• Config# ip route Net_AddSN_MaskNext_Hop_Add – Example: ip route 192.168.15.0 255.255.255.0 205.5.5.2
• Config# ip route 0.0.0.0 0.0.0.0Next_Hop_Add – Default route
  -or-
• Config# ip default-network Net_Add – Gateway LAN networkIP ROUTING:
• Config# ip routing – Enabled by default
• Config# router rip
  -or-
• Config# router igrp 100
• Config# interface Ethernet 0
• Config-if# ip address 122.2.3.2 255.255.255.0
• Config-if# no shutdownIPX ROUTING:
• Config# ipx routing
• Config# interface Ethernet 0
• Config# ipx maximum-paths 2 – Maximum equal metric paths used
• Config-if# ipx network 222 encapsulation sap – Also Novell-Ether, SNAP, ARPA on Ethernet. Encapsulation HDLC on serial
• Config-if# no shutdown
  ACCESS LISTS:

IP STANDARD:

• Config# access-list 10 permit 133.2.2.0 0.0.0.255 – allow all srcip’s on network 133.2.2.0
  -or-
• Config# access-list 10 permit host 133.2.2.2 – specifies a specific host
  -or-
• Config# access-list 10 permit any – allows any address
• Config# int Ethernet 0
• Config-if# ip access-group 10 in – also available: outIP EXTENDED:
• Config# access-list 101 permit tcp 133.12.0.0 0.0.255.255 122.3.2.0 0.0.0.255 eq telnet
  -protocols: tcp, udp, icmp, ip (no sockets then), among others
  -source then destination address
  -eq, gt, lt for comparison
  -sockets can be numeric or name (23 or telnet, 21 or ftp, etc)
  -or-
• Config# access-list 101 deny tcp any host 133.2.23.3 eq www
  -or-
• Config# access-list 101 permit ip any any
• Config# interface Ethernet 0
• Config-if# ip access-group 101 outIPX STANDARD:
• Config# access-list 801 permit 233 AA3 – source network/host then destination network/host
  -or-
• Config# access-list 801 permit -1 -1 – “-1” is the same as “any” with network/host addresses
• Config# interface Ethernet 0
• Config-if# ipx access-group 801 outIPX EXTENDED:
• Config# access-list 901 permit sap 4AA all 4BB all
  – Permit protocol src_add socket dest_add socket
  -“all” includes all sockets, or can use socket numbers
  -or-
• Config# access-list 901 permit any any all any all
  -Permits any protocol with any address on any socket to go anywhere
• Config# interface Ethernet 0
• Config-if# ipx access-group 901 inIPX SAP FILTER:
• Config# access-list 1000 permit 4aa 3 – “3” is the service type
  -or-
• Config# access-list 1000 permit 4aa 0 – service type of “0” matches all services
• Config# interface Ethernet 0
• Config-if# ipx input-sap-filter 1000 – filter applied to incoming packets
  -or-
• Config-if# ipx output-sap-filter 1000 – filter applied to outgoing packetsNAMED ACCESS LISTS:
• Config# ip access-list standard LISTNAME
  -can be ip or ipx, standard or extended
  -followed by the permit or deny list
• Config# permit any
• Config-if# ip access-group LISTNAME in
  -use the list name instead of a list number
  -allows for a larger amount of access-listsPPP SETUP:
• Config-if# encapsulation ppp
• Config-if# ppp authentication chap pap
  -order in which they will be used
  -only attempted with the authentification listed
  -if one fails, then connection is terminated
• Config-if# exit
• Config# username Lab-b password 123456
  -username is the router that will be connecting to this one
  -only specified routers can connect
  -or-
• Config-if# ppp chap hostname ROUTER
• Config-if# ppp chap password 123456
  -if this is set on all routers, then any of them can connect to any other
  -set same on all for easy configurationISDN SETUP:
• Config# isdn switch-type basic-5ess – determined by telecom
• Config# interface serial 0
• Config-if# isdn spid1 2705554564 – isdn “phonenumber” of line 1
• Config-if# isdn spid2 2705554565 – isdn “phonenumber” of line 2
• Config-if# encapsulation PPP – or HDLC, LAPDDDR – 4 Steps to setting up ISDN with DDR

1. Configure switch type
   Config# isdn switch-type basic-5ess – can be done at interface config
2. Configure static routes
   Config# ip route 123.4.35.0 255.255.255.0 192.3.5.5 – sends traffic destined for 123.4.35.0 to 192.3.5.5
   Config# ip route 192.3.5.5 255.255.255.255 bri0 – specifies how to get to network 192.3.5.5 (through bri0)
3. Configure Interface
   Config-if# ip address 192.3.5.5 255.255.255.0
   Config-if# no shutdown
   Config-if# encapsulation ppp
   Config-if# dialer-group 1 – applies dialer-list to this interface
   Config-if# dialer map ip 192.3.5.6 name Lab-b 5551212
   connect to lab-b at 5551212 with ip 192.3.5.6 if there is interesting traffic
   can also use “dialer string 5551212” instead if there is only one router to connect to
4. Specify interesting traffic
   Config# dialer-list 1 ip permit any
   -or-
   Config# dialer-list 1 ip list 101 – use the access-list 101 as the dialer list
5. Other Options
   Config-if# hold-queue 75 – queue 75 packets before dialing
   Config-if# dialer load-threshold 125 either
   -load needed before second line is brought up
   -“125” is any number 1-255, where % load is x/255 (ie 125/255 is about 50%)
   -can check by in, out, or either
   Config-if# dialer idle-timeout 180
   -determines how long to stay idle before terminating the session
   -default is 120

FRAME RELAY SETUP:

• Config# interface serial 0
• Config-if# encapsulation frame-relay – cisco by default, can change to ietf
• Config-if# frame-relay lmi-type cisco – cisco by default, also ansi, q933a
• Config-if# bandwidth 56
• Config-if# interface serial 0.100 point-to-point – subinterface
• Config-if# ip address 122.1.1.1 255.255.255.0
• Config-if# frame-relay interface-dlci 100
  -maps the dlci to the interface
  -can add BROADCAST and/or IETF at the end
• Config-if# interface serial 1.100 multipoint
• Config-if# no inverse-arp – turns IARP off; good to do
• Config-if# frame-relay map ip 122.1.1.2 48 ietf broadcast
  -maps an IP to a dlci (48 in this case)
  -required if IARP is turned off
  -ietf and broadcast are optional
• Config-if# frame-relay map ip 122.1.1.3 54 broadcast

SHOW COMMANDS

• Show access-lists – all access lists on the router
• Showcdp – cdp timer and holdtime frequency
• Showcdp entry * – same as next
• Showcdp neighbors detail – details of neighbor with ip add and ios version
• Showcdp neighbors – id, local interface, holdtime, capability, platform portid
• Showcdp interface – int’s running cdp and their encapsulation
• Showcdp traffic – cdp packets sent and received
• Show controllers serial 0 – DTE or DCE status
• Show dialer – number of times dialer string has been reached, other stats
• Show flash – files in flash
• Show frame-relay lmi – lmi stats
• Show frame-relay map – static and dynamic maps for PVC’s
• Show frame-relay pvc – pvc’s and dlci’s
• Show history – commands entered
• Show hosts – contents of host table
• Showint f0/26 – stats of f0/26
• Show interface Ethernet 0 – show stats of Ethernet 0
• Showip – ipconfig of switch
• Showip access-lists – ip access-lists on switch
• Showip interface – ipconfig of interface
• Showip protocols – routing protocols and timers
• Showip route – Displays IP routing table
• Showipx access-lists – same, only ipx
• Showipx interfaces – RIP and SAP info being sent and received, IPX addresses
• Showipx route – ipx routes in the table
• Showipx servers – SAP table
• Showipx traffic – RIP and SAP info
• Show isdn active – number with active status
• Show isdn status – shows if SPIDs are valid, if connected
• Showmac-address-table – contents of the dynamic table
• Show protocols – routed protocols and net_addresses of interfaces
• Show running-config – dram config file
• Show sessions – connections via telnet to remote device
• Show startup-config – nvramconfig file
• Show terminal – shows history size
• Show trunk a/b – trunk stat of port 26/27
• Show version – ios info, uptime, address of switch
• Showvlan – all configured vlan’s
• Showvlan-membership – vlan assignments
• Showvtp – vtpconfigs

CATALYST COMMANDS
For Native IOS – Not CatOS
SWITCH ADDRESS:

• Config# ip address 192.168.10.2 255.255.255.0
• Config# ip default-gateway 192.168.10.1DUPLEX MODE:
• Config# interface Ethernet 0/5 – “fastethernet” for 100 Mbps ports
• Config-if# duplex full – also, half | auto | full-flow-controlSWITCHING MODE:
• Config# switching-mode store-and-forward – also, fragment-freeMAC ADDRESS CONFIGS:
• Config# mac-address-table permanent aaab.000f.ffef e0/2 – only this mac will work on this port
• Config# mac-address-table restricted static aaab.000f.ffef e0/2 e0/3
  -port 3 can only send data out port 2 with that mac
  -very restrictive security
• Config-if# port secure max-mac-count 5 – allows only 5 mac addresses mapped to this portVLANS:
• Config# vlan 10 name FINANCE
• Config# interface Ethernet 0/3
• Config-if# vlan-membership static 10TRUNK LINKS:
• Config-if# trunk on – also, off | auto | desirable | nonegotiate
• Config-if# no trunk-vlan 2
  -removes vlan 2 from the trunk port
  -by default, all vlans are set on a trunk portCONFIGURING VTP:
• Config# delete vtp – should be done prior to adding to a network
• Config# vtp server – the default is server, also client and transparent
• Config# vtp domain Camp – name doesn’t matter, just so all switches use the same
• Config# vtp password 1234 – limited security
• Config# vtp pruning enable – limits vtp broadcasts to only switches affected
• Config# vtp pruning disableFLASH UPGRADE:
• Config# copy tftp://192.5.5.5/configname.ios opcode – “opcode” for ios upgrade, “nvram” for startup configDELETE STARTUP CONFIG:
• Config# delete nvram