Cisco Router show commands

Cisco Networking

SHOW COMMANDS – CISCO ROUTERS (some command relevant to Cisco switches too)

Show version – software version, config files, boot images, config register, basic config of router

Show ipx interface – status, ipx rip and sap received/sent, ipx access-lists

Show ipx route – ipx routing table

Show ipx servers – server list (name, port, hops, type of service)

Show ipx traffic – number/type of packets, RIP and SAP packets

Show protocol – ipx addresses of an interface, IP addresses and routing protocol

Show ip protocol – routing update times, networks active on, neighbour routers, administrative distances, AS number

Show access-lists – shows standard and extended access-lists on all interfaces

Show access-list 101

Show ip interface – IP addresses, masks, MTU, access-lists, split horizon, ICMP, CDP status, NAT statistics, LMI info, DLCIs

Show interface serial 0 – shows bandwidth, MTU, keepalives

Show ip route – ip routing table

Show cdp neighbor – deviceID, local intf, holdtime, capability, platform, remote portID

Show cdp entry * – IP address of neighbour, protocol info, platform, capability, portID, holdtime, same info as show version, neighbour device ID, local interface

Show cdp neighbor detail – same as above also IP address, version info

Show cdp traffic – info on traffic and errors

Show cdp interface – encapsulation, timer, holdtime for each intf

Show controllers serial 0 – shows DTE/DCE connections, buffer size, collisions, mac address

Show host(s) – shows hostname to IP resolution of hosts

Show session(s) – shows connections to a remote device

Show users – shows connections to your router, port and time connected

Show frame-relay lmi – lmi errors and lmi type

Show frame-relay pvc – all configured PVC’s, DLCI numbers, status of connections, No. of BECN/FECN

Show frame-relay pvc 16

Show frame-relay map – ip to dlci mappings

Show run – display router config (RAM), configured PVCs, ACLs.


Show mac-address-table

Show run

Show ip – like ipconfig

Show port system – shows switching method

Show vtp

Show trunk A allowed-vlans – shows which VLANS allowed on trunk link

Show vlan-membership

Show vlan 2

Show vlan – verify VLAN config

Show history – shows last 10 commands entered by default

Show terminal – shows terminal config + history buffer size


Banner exec – for activation or incoming vty

Banner incoming – displayed on reverse telnet sessions

Banner login – displayed on all connected terminals. Displayed before MOTD banner but before login prompts

Bfe – manual emergency mode setting

Clear counters – clears counters on all interfaces

Clear frame-relay-inarp – clears dynamic mappings

Clear line 1 – clears vty 1 connection to a remote router

Clock set 10.30.10 28 may 2002

Config-register 0x2102 – changes config register

Copy flash tftp

Copy tftp flash – copies IOS image from tftp server default directory to router flash

Disable – to get back to user mode from privileged

Disconnect 1 – clears a connection to a remote router

Enable – to get into privileged mode

Enable last-resort – define enable action if no tacas servers respond

Enable use-tacas – tells the router to authenticate passwords through a tacas server

Encapsulation isl 3 – encapsulates ISL frame-tagging for VLAN 3 on an interface

Exec timeout 0 1 – sets console timeout to 1 second

Exec-timeout 0 0 – sets exec timeout to never timeout

Exec-timeout 1 0 – set exec timeout to 1 minute

Ip domain-lookup – enables DNS (use no form to stop this)

Ip domain-name – appends domain name to hostname (required for DNS)

Ip host nik – adds to host table (up to 8 ip addr)

Ip name-server – sets ip address(es) of DNS servers

Lock – locks the terminal

Logging synchronous – stops console messages overwriting commands

Logout – to logout of the router

Media-type 100BaseX – sets media type

Mrinfo – request neigbour and version information from a multicast router

No login – sets line, vty ports not to prompt for login info

Passive-inteface s0 – disables routing updates on interface (Global command) – they are not sent out this interface but they are still received.

Ping ipx 40.0000.0c8d.5c9d

Service password-encryption – encrypts passwords (Global command)

Terminal monitor – needed to view debug commands from telnet session

Terminal history size 50 – sets command history to 50 lines

Tftp-server system – Make router a tftp server


Interface Ethernet 2/0/1 – type slot / port adapter / port number (interface) for VIP cards

Config terminal – configures RAM

Config network (config net) – changes a config on a tftp host

Config memory – configure NVRAM

Ip address secondary – adds a secondary subnet address to an interface

Clock rate 56000 – sets clock rate to 56kbps for DCE interfaces


Access-enable – creates a temporary access-list entry

Access-template – creates a temporary access-list entry

Access-profile – apply user profile to interface

Access-list 1 permit – same as next line

Access-list 1 permit any – permits any host

Access-list 1 permit – same as next line

Access-list 1 permit host – permits host

No access list 1 – deletes access list 1

Ip access-group 1 out (out is default)

Access-list 101 deny tcp any eq telnet

Access-list 101 permit ip any any established (TCP connection)

Router(Config)#ip access-list standard nik

Router(Config std-nacl)#deny any log (log – logs packets)

No ip access-group in – won’t delete inbound lists if you leave the in off the end of the command


Router(Config)#int s0

Router(Config-if)#encapsulation frame-relay cisco (default)


Router(Config)#int s0.16 point-to-point

Router(Config-if)#no inverse-arp

Router(Config-if)#ip address

Router(Config-if)#bandwidth 64 – sets bandwidth to 64kbps (Only used by routing protocols)

Router(Config-if)#frame-relay map ip 16 ietf broadcast – broadcast tells the router to send broadcasts out this intf


Router(Config)#router igrp 50

Router(Config-router)#timers basic 15 45 0 60

Router(Config-router)#variance 1-128 (controls load balancing between best and worse metrics)

Router(Config-router)#traffic-share balanced/min

Balanced – share inversely proportional to metrics

Min – use routers that have only min costs


Router(Config-router)#no metric holddown

Router(Config-router)#metric maximum-hop 50


Router(Config)#ipx routing – enables IPX routing, RIP and SAP

Router(Config)#ipx maximum-paths 2 – enables equal cost load balancing over 2 paths

Router(Config)#ipx per-host-load-share – ensures all packets to 1 destination are sent over same line

Router(Config)#int e0

Router(Config-if)#ipx network 10 encapsulation sap secondary – assigns ipx network 10 to a secondary interface on Ethernet 0 with encapsulation Ethernet_802.2

Router(Config-if)#ipx delay 6 – sets tick metric for IPX RIP (LAN = 1, WAN = 6 default)



Router(Config)#interface bri 0

Router(Config-if)#ip address

Router(Config-if)#no shutdown

Router(Config-if)#dialer-group 1

Router(Config-if)#dialer map ip name 8042 8350661

(Next router ip – hostname of next route (auth) – number to dial)

Router(Config-if)#dialer load-threshold 2 either – makes both interfaces come up immediately

Router(Config-if)#dialer load-threshold 255 either – only brings up 2nd B-channel if first is 100% loaded

Router(Config-if)#hold-queue 75 in – holds 75 packets in the queue during connection

Router(Config-if)#dialer idle-timeout 300 – sets idle time out (120 default)

Router(Config-if)#encapsulation ppp


Router(Config)#dialer-list 1 list 110

Router(Config)#access-list 110 permit tcp any any eq smtp

Router(Config)#access-list 110 permit tcp any any eq telnet


Ip route = default route

Ip default-network

Ip route serial 1 1 permanent – keeps static route even if router cannot communicate with it, administration distance 1


Cdp timer 90

Cdp holdtime 240

Cdp enable (no cdp enable)


#config t

(Config)#enable password level 1 nikolas – usermode password

(Config)#enable password level 15 makris – enable password

(Config)#enable secret nik2 – precedes the enable p/w

(Config)#hostname nik

(Config)#vtp pruning enable – enables pruning on whole switch

(Config)#delete vtp – deletes VTP database

(Config)#vtp server (client/transparent)

(Config)#vtp domain nikolas

(Config)#vtp password cisco

(Config)#ip address

(Config)#ip default-gateway

(Config)#switching-mode store-and-forward (fragment-free)

(Config)#vlan 2 name sales

(Config)#vlan 3 name marketing

(Config)#int Ethernet 0/1 – slot 0/port 1

(Config-if)#vlan-membership static 2

(Config-if)#description Finance_VLAN

(Config-if)#port secure max-mac-count 1 – allows only one mac address per port


(Config)#int f0/26

(Config-if)#trunk on – enables trunking of all VLANS not just VLAN 1

(Config-if)#no trunk-vlan 3 – stops trunking vlan 3

(Config-if)#duplex full – sets to full duplex (auto sense default)


(Config)#copy tftp:// opcode – download into flash memory

(Config)#copy nvram tftp://

(Config)#copy tftp:// nvram

(Config)#delete nvram – deletes config

(Config)#delete vtp – deletes VTP database

(Config)#clear mac-address-table [dynamic]


Debug ipx routing activity – info on RIP updates

Debug ipx sap – info on sap updates

Debug ip igrp events – what’s being rec’d sent, route type (int/ext,system), source, dest

Debug ip igrp transactions – shows contents of routing updates

Debug ip rip – source/contents of updates, network, metrics

Debug frame-relay lmi – enables verification of connection

Debug ppp authentication


Turn of debugging.