Cisco IOS è un sistema operativo per dispositivi di rete router e switch della società Cisco Systems, installato attualmente su tutti gli switch e sulla maggior parte dei router della stessa ditta, che costituiscono circa l’80% degli switch della rete mondiale.
Si tratta di un sistema molto semplice senza interfaccia grafica bensi’ a riga di comando. A seconda dei diritti di lettura, scrittura ed esecuzione dell’operatore e della modalità con cui egli ha avuto accesso, il sistema mette a disposizione una serie di comandi predefiniti.
La seguente tabella mostra i principali comandi per la configurazione:
| Operazioni di Base | |
| FUNZIONE | COMANDO |
| Enable | Enter privileged mode |
| Return to user mode from privileged | disable |
| Exit Router | Logout or exit or quit |
| Recall last command | up arrow or <Ctrl-P> |
| Recall next command | down arrow or <Ctrl-N> |
| Suspend or abort | <Shift> and <Ctrl> and 6 then x |
| Refresh screen output | <Ctrl-R> |
| Compleat Command | TAB |
| Comandi di Configurazione | |
| FUNZIONE | COMANDO |
| Set a console password to cisco | Router(config)#line con 0 Router(config-line)#login Router(config-line)#password cisco |
| Set a telnet password | Router(config)#line vty 0 4 Router(config-line)#login Router(config-line)#password cisco |
| Stop console timing out | Router(config)#line con 0 Router(config-line)#exec-timeout 0 0 |
| Set the enable password to cisco | Router(config)#enable password cisco |
| Set the enable secret password to peter.This password overrides the enable password and is encypted within the config file | Router(config)#enable secret peter |
| Enable an interface | Router(config-if)#no shutdown |
| To disable an interface | Router(config-if)#shutdown |
| Set the clock rate for a router with a DCE cable to 64K | Router(config-if)clock rate 64000 |
| Set a logical bandwidth assignment of 64K to the serial interface | Router(config-if)bandwidth 64 Note that the zeroes are not missing |
| To add an IP address to a interface | Router(config-if)#ip addr 10.1.1.1 255.255.255.0 |
| To enable RIP on all 172.16.x.y interfaces | Router(config)#router rip Router(config-router)#network 172.16.0.0 |
| Disable RIP | Router(config)#no router rip |
| To enable IRGP with a AS of 200, to all interfaces | Router(config)#router igrp 200 Router(config-router)#network 172.16.0.0 |
| Disable IGRP | Router(config)#no router igrp 200 |
| Static route the remote network is 172.16.1.0, with a mask of 255.255.255.0, the next hop is 172.16.2.1, at a cost of 5 hops | Router(config)#ip route 172.16.1.0 255.255.255.0 172.16.2.1 5 |
| Disable CDP for the whole router | Router(config)#no cdp run |
| Enable CDP for he whole router | Router(config)#cdp run |
| Disable CDP on an interface | Router(config-if)#no cdp enable |
| Comandi di Show | |
| FUNZIONE | COMANDO |
| View version information | show version |
| View current configuration (DRAM) | show running-config |
| View startup configuration (NVRAM) | show startup-config |
| Show IOS file and flash space | show flash |
| Shows all logs that the router has in its memory | show log |
| View the interface status of interface e0 | show interface e0 |
| Overview all interfaces on the router | show ip interfaces brief |
| View type of serial cable on s0 | show controllers 0 (note the space between the ‘s’ and the ‘0’) |
| Display a summary of connected cdp devices | show cdp neighbor |
| Display detailed information on all devices | show cdp entry * |
| Display current routing protocols | show ip protocols |
| Display IP routing table | show ip route |
| Display access lists, this includes the number of displayed matches | show access-lists |
| Check the router can see the ISDN switch | show isdn status |
| Check a Frame Relay PVC connections | show frame-relay pvc |
| show lmi traffic stats | show frame-relay lmi |
| Display the frame inverse ARP table | show frame-relay map |
| Comandi di copia | |
| FUNZIONE | COMANDO |
| Save the current configuration from DRAM to NVRAM | copy running-config startup-config |
| Merge NVRAM configuration to DRAM | copy startup-config running-config |
| Copy DRAM configuration to a TFTP server | copy runing-config tftp |
| Merge TFTP configuration with current router configuration held in DRAM | copy tftp runing-config |
| Backup the IOS onto a TFTP server | copy flash tftp |
| Upgrade the router IOS from a TFTP server | copy tftp flash |
| Comandi di debug | |
| FUNZIONE | COMANDO |
| Enable debug for RIP | debug ip rip |
| Enable summary IGRP debug information | debug ip igrp events |
| Enable detailed IGRP debug information | debug ip igrp transactions |
| Debug IPX RIP | debug ipx routing activity |
| Debug IPX SAP | debug IPX SAP |
| Enable debug for CHAP or PAP | debug ppp authentication |
| Switch all debugging off | no debug allundebug all |
