Bottom line: To earn your Cisco CCNA and CCENT certifications, you have got to recognize the configuration check in on Cisco routers and switches. This is likewise a amazing realistic ability to have, due to the fact sooner or later you may need to alternate the config sign up, maximum probably to carry out a password recuperation.
I will simply supply this caution one time: If you change the sign in to an wrong cost after which reload the router, you may cripple the router or even Cisco cannot bring it back.
No stress, proper? 🙂
You genuinely just should be cautious and get the proper fee for what you are seeking to do earlier than you convert the config sign up. Another key is to alternate the check in back to the original cost when you’re done together with your paintings.
To see the modern-day config register price, run the constantly-useful command display model. The config check in price is at the very backside of that output, but while we are here, permit’s check all of this records.
Cisco Internetwork Operating System Software
IOS ™ 2500 Software (C2500-I-L), Version 12.1(20), RELEASE SOFTWARE (fc2)
Copyright (c) 1986-2003 by means of cisco Systems, Inc.
Compiled Thu 29-May-03 22:00 by using kellythw
Image text-base: 0x03041F34, data-base: 0x00001000
ROM: System Bootstrap, Version eleven.0(10c)XB1, PLATFORM SPECIFIC RELEASE SOFTWARE
BOOTLDR: 3000 Bootstrap Software (IGS-BOOT-R), Version eleven.0(10c)XB1, PLATFORM SP
ECIFIC RELEASE SOFTWARE (fc1)
Router1 uptime is four days, 10 hours, forty three minutes
System again to ROM through reload
System image record is “flash:/c2500-i-l.121-20.Bin”
cisco 2521 (68030) processor (revision L) with 14336K/2048K bytes of reminiscence.
Processor board ID 22066955, with hardware revision 00000003
X.25 software program, Version three.0.0.
Basic Rate ISDN software program, Version 1.1.
1 Token Ring/IEEE 802.5 interface(s)
2 Serial community interface(s)
2 Low-pace serial(sync/async) community interface(s)
1 ISDN Basic Rate interface(s)
32K bytes of non-volatile configuration memory.
16384K bytes of processor board System flash (Read ONLY)
Configuration sign up is 0x2102
The first bolded field tells you what IOS software and version this router is running.
The 2d bolded area suggests you ways lengthy the router’s been up, why the router went down (“reload”), and the IOS document contained in flash.
Below that, however no longer bolded, is a listing of interfaces on the router and the potential of NVRAM and Flash.
The 1/3 bolded subject suggests you the quantity of NVRAM your router has. Since the startup config document is stored there, it is as big because the startup config report can get!
Finally, the all-essential config register cost. You’ll learn about manipulating the config sign up at some stage in your CCNA research, however you need to understand that the price shown, 0x2102, is the factory default. This value forces the router to appearance in its own Flash reminiscence for a valid IOS on startup.
The config-register fee does require a reload for a modified fee to take impact. I’ll alternate this value to 0x2142 and run show model once more, cropping out all statistics besides the config-sign up. The sign in placing 0x2142 forces the router to pass the startup configuration document kept in NVRAM.
Router1(config)#config-sign in 0x2142
Configuration register is 0x2102 (may be 0x2142 at next reload)
Like debugs, the config-register command have to be used with warning.
Another commonplace fee used with config-register is 0x2100, which boots the router into ROM Monitor mode.
To evaluate these commonplace configuration sign up settings:
0x2102: The default. Router looks for a startup configuration document in NVRAM and for a valid IOS photograph in Flash.
0x2142: NVRAM contents are bypassed, startup configuration is disregarded.
0x2100: Router boots into ROM Monitor mode.
A real-international reminder: When you change the configuration sign in price to carry out password recuperation, do not forget to exchange it back after which reload the router!
Chris Bryant, CCIE #12933, is the owner of The Bryant Advantage, home of loose CCNA 640-802 CBTs, CCNA 640-802 tutorials, The Ultimate CCNA Study Package, and Ultimate CCNP Study Packages.
You also can go to his blog, that’s updated numerous times each day with new Cisco certification articles, unfastened tutorials, and daily CCNA / CCNP exam questions!