IOS... how to upgrade? IOS with SSH

[Sniffer2112]

I saw a video on how to upgrade your IOS with TFTP. My questions is, when you install a new IOS, does it overwrite the old one? Are there any tips to doing this? I've never done this before so I would hate to really mess this up.

Also, this training video talks about setting up SSH on your router. My current IOS is: c2600-is-mz.122-15.T10.bin

When I try to do SSH, it never works. Like the crypto command is not recognized. I thought I read somewhere that your IOS has to have a 'k' in it if you want SSH. Is this true? Or can someone point to a website that explains how to read the IOS.bin names?

I really appreciate any help
Thanks!

 

[CiscoGuy33]

Sniffer2112,

Are you working on a lab or a production router?

"I saw a video on how to upgrade your IOS with TFTP. My questions is, when you install a new IOS, does it overwrite the old one?"

Yes, normally it will erase FLASH before it moves the new IOS in. Depending on the size of FLASH would determine if you can have more than 1 IOS in there. BEFORE you do anything, you should backup your current IOS - "just in case"

As for how to do it - try the console cable and hyperterminal to start, you can read more here -

http://www.cisco.com/en/US/products/hw/routers/ps259/products_tech_note09186a00801fc986.shtml

When doing ANYTHING on your router - Google and

http://www.cisco.com

is your best friend

Hope this helps!

E.A. Broda
CCNA, CCDA, CCAI, Network +

 

[burtsbees]

Actually, it asks if you want to erase the flash. If it is big enough to hold 2 IOS files, then you don't have to. You would boot to whichever IOS by
router(config)#boot system flash:ios_image_name.bin

Burt

 

[Sniffer2112]

Thank you CiscoGuy33. That does help a lot. I'm still trying to find my way around the Cisco web site. There is a lot of information in there.

And to answer your fist question, this is for my lab router. And yes, I did back up my ios and start-config file.

If I remember right my router has 32 MB of RAM so I'm sure I can only have 1 IOS.

 

[CiscoGuy33]

Sniffer2112,

If you are working on a lab router and working towards a Cisco cert - you should visit us over at the Cisco Cert forum here at Tek-Tips

A little more on your router, if it is a Cisco 26xx router like a 2611 or 2610 then MAX DRAM is 64 and MAX FLASH is 16. The IOS is going into FLASH and is loaded into RAM when the router boots.

Do a "show version" and it will tell you the amount of DRAM and FLASH.

Here is a "show version for a 2600, first bold is the DRAM second bold is the FLASH -

Cisco Internetwork Operating System Software
IOS (tm) C2600 Software (C2600-IO3-M), Version 12.3(26), RELEASE SOFTWARE (fc2)
Technical Support:

http://www.cisco.com/techsupport

Copyright (c) 1986-2008 by cisco Systems, Inc.
Compiled Mon 17-Mar-08 15:23 by dchih

ROM: System Bootstrap, Version 11.3(2)XA4, RELEASE SOFTWARE (fc1)

Router uptime is 0 minutes
System returned to ROM by power-on
System image file is "flash:c2600-io3-mz.123-26.bin"

cisco 2611 (MPC860) processor (revision 0x203) with 45056K/4096K bytes of memory.
M860 processor: part number 0, mask 49
Bridging software.
X.25 software, Version 3.0.0.
Basic Rate ISDN software, Version 1.1.
2 Ethernet/IEEE 802.3 interface(s)
1 ISDN Basic Rate interface(s)
32K bytes of non-volatile configuration memory.
8192K bytes of processor board System flash (Read/Write)

Configuration register is 0x2102

Like Burt said, if you have enough FLASH and the IOS image is small, you could have 2 or more IOS's in FLASH and then tell the router which to boot to such as in a dual boot computer

You can do a "show flash" to see what you do have in FLASH and how much memory is available.

"I'm still trying to find my way around the Cisco web site. There is a lot of information in there."

Yes, the Cisco site is huge, nice thing is that when you "Google" most things "Cisco", links to Cisco are normally in the top 10 searchs returned.

Hope this helps, and come visit us over in the other forum here!

E.A. Broda
CCNA, CCDA, CCAI, Network +

 

[vipergg]

The version of code you posted c2600-is-mz.122-15.T10.bin is not SSH capable you will need to download a new version that has crypto capability . Usually the imagename will have a "k9" somewhere in the name . Until you get this no ssh config commands will work .

 

[Sniffer2112]

Ran into a SNAFU. I tried to load an IOS which was bigger than the memory I have installed. So now it keeps going to the ROMMON >1 prompt.

I'll have to figure out how to boot from a TFTP server and load the original IOS again.

I'll keep posting so others can learn from this.

I did see that memory was cheap on eBay. Worst case is I spend a few $$$ and bump up the memory so the IOS will load.

 

[CiscoGuy33]

Sniffer2112,

For DRAM and FLASH that works with Cisco routers - check

http://www.anthonypanda.com

I was at a Cisco convention several years ago and all the CCIE's kept talking about getting stuff for their labs at Anthony Panda

I checked it out when I got home and have bought from him several times, in fact bought enough FLASH and DRAM to upgrade 20 routers at work and all worked GREAT.

To load a new IOS from ROMON put in the "?" and look at the menu, you need to set

To load an IOS onto a router using ROMmon mode via Ethernet cable:

Start the TFTP server

Connect to the router via Ethernet cable (an Ethernet cable is preferred due to the large size of the file and the maximum speed that data can travel over the console cable)

Before the IOS is loaded it is important to make sure that your router has enough memory to support the IOS. The router will allow an IOS to be loaded even if there is not enough memory, in this case a smaller IOS will have to be loaded.

At the rommon prompt enter the following commands (commands are case sensitive, and the use of the directional arrows and tab auto complete function is not allowed):

IP_ADDRESS=IP address of the Ethernet port
IP_SUBNET_MASK=subnet mask of the Ethernet port
DEFAULT_GATEWAY=the default gateway
TFTP_SERVER=the IP of the TFTP server (your local computer)
TFTP_FILE=the file name of the IOS file

Type in -

tftpdnld

The router will then issue a warning message:

Invoke this command for disaster recovery only.
WARNING: all existing data in all partitions on flash will be lost!
Do you wish to continue? y/n: [n]: y

Enter y, and the IOS will load
Once loaded you must boot up the new IOS by issuing the boot command

-------------------------------------------

Hope this helps!

E.A. Broda
CCNA, CCDA, CCAI, Network +

 

[CiscoGuy33]

Sniffer2112,

An example of this would be - lets say your computer 192.168.1.6 is running your TFTP server and the file you want is c2600-is-mz.122-15.T10.bin


IP_ADDRESS=192.168.1.1
IP_SUBNET_MASK=255.255.255.0
DEFAULT_GATEWAY=192.168.1.1
TFTP_SERVER=192.168.1.6
TFTP_FILE=c2600-is-mz.122-15.T10.bin

Make sure Ethernet cable is in E0/0 and is in same hub/switch that the TFTP server is in, if you are connecting directly to TFTP you will need a cross-over cable.

I have done this many times when students erase FLASH by mistake !!!!

Have fun!!

E.A. Broda
CCNA, CCDA, CCAI, Network +

 

[Sniffer2112]

Thanks for the help CiscoGuy. All was going well when I realized that the FastEthernet port was not configured. So I had to pull memory from one router and put it in the router that I was working on. Now it boots up just fine to the new IOS. I was able to find some really cheap 128MB memory on ebay. So I'll upgrade all the routers.

Side question (maybe I should start a new post for those wondering the same thing)....

Turning off the router... what is the best way or is there? I've been flipping off the switch but should you do something at the command line to prepare the router to turn off? Or is it ok to just kill the power. Same thing for switches?

 

[stubnski]

There is no command to power off Cisco switches or routers. You could use a manageable power switches to do that remotely.


Stubnski

 

[burtsbees]

You should realize that some of the older equipment that have no power switch (2500 series routers, 2900XL series switches), where you have to simply pull power, may boot back up into rommon, as they see the pulling the plug as a sudden loss of AC. This is the only way to kill those, though---no IOS commands to prepare for a shutdown (like Windoze...lol)---additionally, once you hit enter after a command in a Cisco device, it takes place right away (except for maybe ip add dhcp, ddns commands, and others that need an obvious reboot). No need to reboot (again, like Windoze)...
Now the other routers and switches that do have a power switch (3640 router, for example)---this kills DC to the router, so no "sudden loss of AC", and unless there is something else wrong like a module not being recognized, etc., the router would not boot into rommon.

Burt