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Regarding IPSec configuration on Cisco 1841 Router

Hi team,

We have a Cisco Router 1841 , following is  the show  version output. I am trying to configure the IPSec on this but it is not accepting the Crypto commands. May i know the reason for that and also request you to give the compatible version of the IOS Software and Path to download so that i will install and will configure the IPSec on the same Router.

Router#sh version
Cisco IOS Software, 1841 Software (C1841-IPBASE-M), Version 12.4(17b), RELEASE S
Technical Support:
Copyright (c) 1986-2008 by Cisco Systems, Inc.
Compiled Mon 25-Feb-08 20:59 by prod_rel_team

ROM: System Bootstrap, Version 12.4(13r)T, RELEASE SOFTWARE (fc1)

Router uptime is 5 weeks, 6 days, 3 hours, 0 minutes
System returned to ROM by power-on
System image file is "flash:c1841-ipbase-mz.124-17b.bin"

Cisco 1841 (revision 7.0) with 97280K/33792K bytes of memory.
Processor board ID FHK12162444
2 FastEthernet interfaces
2 Serial(sync/async) interfaces
DRAM configuration is 64 bits wide with parity disabled.
191K bytes of NVRAM.
31360K bytes of ATA CompactFlash (Read/Write)

Configuration register is 0x2102



CMC Ltd.

Cisco Employee

Re: Regarding IPSec configuration on Cisco 1841 Router

Hi Ramu,

The reason you are not able to apply crypto config is because i think the C1841-IPBASE-M does not support this. You can use the feature navigator tool ( ) for identifing which software supports what feature.

For IPsec support, you need to use ADVANCED ENTERPRISE SERVICES feature Set/License for the same version. The IOS image name would be somthing like:


You can download the above software from the Cisco's software download section. You can reach this section from

Let me know if this helps,

Rudresh V