Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 
New Member

IOS Upgrade

I Have a router 1720. The ios ver is 12.0(4)T. I want to upgrade to the newest ver 12.4(25a). What should I consider before I upgrade. I have no this kind of experience before. Should I consider memory is enough for the new ver? Can I directly upgrade to the new ver? Anyone can provide this kind information or any link I can check it? This router is not on production.

Another question: Do I need to upgrade bootstrap? Or is it included in IOS?


Cisco Employee

Re: IOS Upgrade

Can you post the output of show version? That will show us how much memory and disk is in your 1720 currently and which IOS you can go with. You can use Software Advisor to find out the memory, and disk requirement, and software features of the IOS

You can upgrade directly to any new version if you have enough memory.

No you don't need to upgrade the bootstrap. Most likely, the bootstrap for the 1700 router is a chip.



New Member

Re: IOS Upgrade


thanks for help. Here is the output of show version.

Router>sh ver

Cisco Internetwork Operating System Software

IOS (tm) C1700 Software (C1700-Y-M), Version 12.0(4)T, RELEASE SOFTWARE (fc1)

Copyright (c) 1986-1999 by cisco Systems, Inc.

Compiled Wed 28-Apr-99 14:34 by kpma

Image text-base: 0x80008088, data-base: 0x805133AC

ROM: System Bootstrap, Version 12.0(3)T, RELEASE SOFTWARE (fc1)

Router uptime is 2 hours, 15 minutes

System restarted by power-on

System image file is "flash:c1700-y-mz.120-4.T"

cisco 1720 (MPC860) processor (revision 0x301) with 12288K/4096K bytes of memory


Processor board ID JAD03391271 (3946282433), with hardware revision 0000

M860 processor: part number 0, mask 32

Bridging software.

X.25 software, Version 3.0.0.

1 FastEthernet/IEEE 802.3 interface(s)

1 Serial network interface(s)


32K bytes of non-volatile configuration memory.

4096K bytes of processor board System flash (Read/Write)

Configuration register is 0x2102


Hall of Fame Super Bronze

Re: IOS Upgrade

You will need to upgrade Memory and Flash on this router as current version(s) require at least 48MB DRAM and 16MB Flash.

You currently have 16MB DRAM and 4MB Flash.



New Member

Re: IOS Upgrade

Thanks very much for your information.

I hvae one more question for IOS version. When I go to Cisco web download IOS, it will popout a large variety of choices, like IP, IP/ADSL, IP PLUS, IP/IPX, IP/FW/IDS PLUS IPSEC 3DES... I have no idea which one is the right one for me. IS there any document for these names? Or it doesn't matter only if the memory can fit it? From the name, I probably can guess its usage. But I just want to find out whta it stands for.

Cisco Employee

Re: IOS Upgrade

Different feature sets support additional commands and hardware. Realistically, you need to have the license to change to different feature sets.

You can compare it with the Software Advisor tool.



CreatePlease to create content