It might happen on your CCNA exam, it might happen on your production network - but sooner or later, you're going to have to perform password recovery on a Cisco router or switch. This involves manipulating the router's configuration register, and that is enough to make some CCNA candidates and network administrators really nervous!
It's true that setting the configuration register to the wrong value can damage the router, but if you do the proper research before starting the password recovery process, you'll be fine.
Despite what some books say, there is no "one size fits all" approach to Cisco password recovery. What works on a 2500 router may not work on other routers and switches. There is a great master Cisco document out on the Web that you should bookmark today. Just put "cisco password recovery" in your favorite search engine and you should find it quickly.
The following procedure describes the process in recovering from a lost password on a Cisco 2500 router. As always, don't practice this at home. It is a good idea to get some practice with this technique in your CCNA / CCNP home lab, though!
The password recovery method examined here is for 2500 routers.
An engineer who finds themselves locked out of a router can view and change the password by changing the configuration register.
The router must first be rebooted and a "break" performed within the first 60 seconds of the boot process. This break sequence can also vary depending on what program is used to access the router, but is the usual key combination.
The router will now be in ROM Monitor mode. From the rom monitor prompt, change the default configuration register of 0x2102 to 0x2142 with the o/r 0x2142 command. Reload the router with the letter i. (As you can see, ROM Monitor mode is a lot different than working with the IOS!)
This particular config register setting will cause the router to ignore the contents of NVRAM. Your startup configuration is still there, but it will be ignored on reload.
When the router reloads, you'll be prompted to enter Setup mode. Answer "N", and type enable at the router> prompt.
Be careful here. Type configure memory or copy start run. Do NOT type write memory or copy run start!
Enter the command show running-config. You'll see the passwords in either their encrypted or unencrypted format.
Type config t, then use the appropriate command to set a new enable secret or enable password.
Don't forget to change the configuration register setting back to the original value! The command config-register 0x2102 will do the job. Save this change with write memory or copy run start, and then run reload one more time to restart the router.
This process sounds hard, but it's really not. You just have to be careful, particularly when you're copying the startup config over the running config. You don't want to get that backwards! So take your time, check the online Cisco documentation before starting, get some practice with this procedure with lab equipment, and you'll be ready for success on the CCNA exam and in your production network!
Senin, 20 Juli 2009
Sabtu, 11 Juli 2009
How to Connect a USB Modem Wireless Router Ethernet
I currently have a USB broadband modem. I purchased a wireless router which has ethernet connections. Currently, the modem is plugged into my computer downstairs which is running Windows 98, therefore, it won't bridge the connections to my computer upstairs(XP). I can't update to XP because a family member wont 'risk' it.
Can I connect the USB broadband modem to my wireless router using a complicated selection of cable adapters ie ethernet to USB (I cant find a USB TO ETHERNET adapter). If this is not possible, if I plug the USB modem into my XP computer, can I bridge the connections to my Win 98 computer using the XP computer as the host?
I think their is Ethernet to USB out their currently but not USB to ethernet. I dont see any reason why you should not be able to hook up your USB modem to your XP computer and use it as a bridge to the 98 computer.
Of course, it would be nicer to have an all-in-one unit, but you can accomplish your goal with this equipment. You cannot use cable adapters to convert the modem's USB into Ethernet. USB needs drivers to operate, and Ethernet connections do not provide those drivers to the device. you could also connect the modem to the XP machine and bridge connections, yes. but you can leave the system the way it is and configure it to run smoothly like this:
If I had the hardwear in front of me, it would be easier to provide specifics... but i can probly give you an idea of what to do. There are only 2 steps here:
1. configure an internet gateway.
2. configure the router.
And the rest is easy.
1. Set up the internet machine to SHARE AN INTERNET CONNECTION (you can use the wizard if you want, or just enable Internet Connection Sharing), which will turn the 98 into an internet gateway. that gateway needs an IP address designated, however. In essence, the 98 machine will be the internet server, so the IP of the 98 machine is the IP of the gateway. Assign an address, for example: 192.168.1.1 to the 98 machine. the "192.168" is important, and the last strings you can stretch on, but for the sake of ease lets keep it small. *TIP* the subnet mask will always be 255.255.255.0. okay that takes care of the host machine.
2. after you have an internet gateway, connect the wireless router, and console (or IP) in to the settings, usually by going into internet explorer and typing 192.168.0.1 into the address bar, and look for a slot for Internet Gateway. Type the address assigned in step 1. thats that for the router. (there may be other settings necessary for your specific network, and if there are, be sure to configure those.)
Lastly a few housekeeping tasks. make sure the workgroup for both machines is identical. I usually use MSHOME as the workgroup. Also make sure that on the XP machine, your IP address is set to "Automatically Obtain IP address", also known as DHCP.
Can I connect the USB broadband modem to my wireless router using a complicated selection of cable adapters ie ethernet to USB (I cant find a USB TO ETHERNET adapter). If this is not possible, if I plug the USB modem into my XP computer, can I bridge the connections to my Win 98 computer using the XP computer as the host?
I think their is Ethernet to USB out their currently but not USB to ethernet. I dont see any reason why you should not be able to hook up your USB modem to your XP computer and use it as a bridge to the 98 computer.
Of course, it would be nicer to have an all-in-one unit, but you can accomplish your goal with this equipment. You cannot use cable adapters to convert the modem's USB into Ethernet. USB needs drivers to operate, and Ethernet connections do not provide those drivers to the device. you could also connect the modem to the XP machine and bridge connections, yes. but you can leave the system the way it is and configure it to run smoothly like this:
If I had the hardwear in front of me, it would be easier to provide specifics... but i can probly give you an idea of what to do. There are only 2 steps here:
1. configure an internet gateway.
2. configure the router.
And the rest is easy.
1. Set up the internet machine to SHARE AN INTERNET CONNECTION (you can use the wizard if you want, or just enable Internet Connection Sharing), which will turn the 98 into an internet gateway. that gateway needs an IP address designated, however. In essence, the 98 machine will be the internet server, so the IP of the 98 machine is the IP of the gateway. Assign an address, for example: 192.168.1.1 to the 98 machine. the "192.168" is important, and the last strings you can stretch on, but for the sake of ease lets keep it small. *TIP* the subnet mask will always be 255.255.255.0. okay that takes care of the host machine.
2. after you have an internet gateway, connect the wireless router, and console (or IP) in to the settings, usually by going into internet explorer and typing 192.168.0.1 into the address bar, and look for a slot for Internet Gateway. Type the address assigned in step 1. thats that for the router. (there may be other settings necessary for your specific network, and if there are, be sure to configure those.)
Lastly a few housekeeping tasks. make sure the workgroup for both machines is identical. I usually use MSHOME as the workgroup. Also make sure that on the XP machine, your IP address is set to "Automatically Obtain IP address", also known as DHCP.
Rabu, 01 Juli 2009
Lenovo IdeaPad S10
This Intel Atom based netbook won’t be breaking any speed records, but it performed more than adequately for normal activities. Windows startup took less than 30 seconds and internet browsing, word processing, and even photo editing tasks were downright “snappy.” While the 3D graphics benchmark numbers aren’t particularly impressive, it’s important to keep in mind that netbooks are not designed for playing computer games. The S10 and similar netbooks are mobile internet portals and productivity tools for getting some quick work done without needing to carry a giant laptop.
Is the Lenovo IdeaPad S10 the best netbook currently on the market and the best value for your dollar? Well, the answer isn’t simple, particularly considering the way that new netbooks seem to arrive every week. The S10 does several things right that we wish more manufacturers did with their netbooks.
First, Lenovo was smart enough to realize and ExpressCard slot is important if you want to make a netbook useful. The ExpressCard slot gives you the option of adding more USB ports, Firewire, eSATA, or any number of other ports to the S10. More importantly, the ExpressCard slot makes it easy to add a broadband modem to the S10 so that you can stay connected to the internet anywhere with cell phone reception.
Second, the S10 has built-in Bluetooth. Frankly, we’re amazed that every netbook doesn’t come with built-in Bluetooth since it allows you to connect devices to the netbook without using one of the USB ports.
Last, but certainly not least the S10 combines the surprisingly capable Intel Atom processor with a standard hard drive. While budget SSDs are nice, most consumers can’t get over the limited storage capacity of SSDs and that is why hard drives still have a place in netbooks.
On the other hand, the S10 still suffers from some of the same limitations as other netbooks: relatively high temperatures, small battery, and a cramped screen and keyboard.
Ultimately, the Lenovo IdeaPad S10 is a great ultra-portable laptop priced below $500. However, if you’re willing to put up with a bulkier notebook then it’s still possible to find a computer with more features and performance for almost the same price on sale.
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