As most things on IOS, show is the way to go.
When you do show version, the last line will tell you the current value of the configuration register. Sample output below.
Router#show version
Cisco Internetwork Operating System Software
IOS (tm) 2500 Software (C2500-JS-L), Version 12.1(5), RELEASE SOFTWARE (fc1)
Copyright (c) 1986-2000 by cisco Systems, Inc.
Compiled Wed 25-Oct-00 05:18 by cmong
Image text-base: 0x03071DB0, data-base: 0x00001000
ROM: System Bootstrap, Version 5.2(8a), RELEASE SOFTWARE
BOOTFLASH: 3000 Bootstrap Software (IGS-RXBOOT), Version 10.2(8a), RELEASE SOFTWARE (fc1)
Router uptime is 7 minutes
System returned to ROM by reload
System image file is "flash:c2500-js-l_121-5.bin"
cisco 2500 (68030) processor (revision D) with 16384K/2048K bytes of memory.
Processor board ID 03867477, with hardware revision 00000000
Bridging software.
X.25 software, Version 3.0.0.
SuperLAT software (copyright 1990 by Meridian Technology Corp).
TN3270 Emulation software.
1 Token Ring/IEEE 802.5 interface(s)
2 Serial network interface(s)
32K bytes of non-volatile configuration memory.
16384K bytes of processor board System flash (Read ONLY)
Configuration register is 0x2102
router>enable router#configure terminal router(config)#line vty 0 4 router(config-line)#password cisco router(config-line)#login to configure router with telnet you must set up password or secret for privilieged mode.
config tftp run
On a Cisco router, that means that you entered interface configuration mode; any command you give will affect the selected interface. For example, you may have given the commands:Router>enableRouter#configure terminalRouter(config)#interface FastEthernet 1/0Router(config-if)#On a Cisco router, that means that you entered interface configuration mode; any command you give will affect the selected interface. For example, you may have given the commands:Router>enableRouter#configure terminalRouter(config)#interface FastEthernet 1/0Router(config-if)#On a Cisco router, that means that you entered interface configuration mode; any command you give will affect the selected interface. For example, you may have given the commands:Router>enableRouter#configure terminalRouter(config)#interface FastEthernet 1/0Router(config-if)#On a Cisco router, that means that you entered interface configuration mode; any command you give will affect the selected interface. For example, you may have given the commands:Router>enableRouter#configure terminalRouter(config)#interface FastEthernet 1/0Router(config-if)#
Data Stored in the NVRAM will be erased
Here is a basic overview of the configuration of RIP on a Cisco router:Router(config)#router ripRouter(config-router)#network 192.168.1.0Router(config-router)#network 192.168.2.0Router(config-router)#network 192.168.3.0Router(config-router)#network 192.168.4.0Router(config-router)#network 192.168.5.0The 192.168.x.0 address can be changed to whatever address you would like to be broadcast over RIP. There are also other settings that can be configured.If you use RIPv2 you can also have the following configuration:Router(config)#router ripRouter(config-router)#version 2Router(config-router)#network 192.168.1.0Router(config-router)#network 192.168.2.0Router(config-router)#network 192.168.3.0Router(config-router)#network 192.168.4.0Router(config-router)#network 192.168.5.0Router(config-router)#exitRouter(config)#exitRouter#%SYS-5-CONFIG_I: Configured from console by consoleRouter#copy running-config startup-configDestination filename [startup-config]?Building configuration...[OK]Router#
That's where the router's startup-config (startup configuration) is stored.That's where the router's startup-config (startup configuration) is stored.That's where the router's startup-config (startup configuration) is stored.That's where the router's startup-config (startup configuration) is stored.
It is short for copy running-config starting-config. Running-config is the configuration of the router as you have modified it and which is currently operating, held in RAM (gone after a reboot), and you copy it to the starting-config which is in NVRAM and gets loaded by the router when it boots/ So essentially you're saving what you have now to the persistent storage so your router will still work after a reboot.
show version
Router(config-if)#no frame-relay lmi-type cisco
(config)#no interface loopback x
First you must decide what specific protocol you want to use. Then you configure it on the individual routers. Example, with Cisco routers: Router(config)#router rip Router(config-router)#network 10.0.0.0. Router(config-router)#exit Additional commands may be required for optimization. Note: I use RIP for illustration purposes, but it is usually not the best option for routing.First you must decide what specific protocol you want to use. Then you configure it on the individual routers. Example, with Cisco routers: Router(config)#router rip Router(config-router)#network 10.0.0.0. Router(config-router)#exit Additional commands may be required for optimization. Note: I use RIP for illustration purposes, but it is usually not the best option for routing.First you must decide what specific protocol you want to use. Then you configure it on the individual routers. Example, with Cisco routers: Router(config)#router rip Router(config-router)#network 10.0.0.0. Router(config-router)#exit Additional commands may be required for optimization. Note: I use RIP for illustration purposes, but it is usually not the best option for routing.First you must decide what specific protocol you want to use. Then you configure it on the individual routers. Example, with Cisco routers: Router(config)#router rip Router(config-router)#network 10.0.0.0. Router(config-router)#exit Additional commands may be required for optimization. Note: I use RIP for illustration purposes, but it is usually not the best option for routing.
The difference is that the write mem command is being discontinued. It is being replaced by the copy command and is the one you should use on the cisco tests. I still use this command on some routers such as 831, 871, 3002, 2950, 2600 however it appears that as of IOS 12 it will be gone. Hope this helps!